Handbook of PolymerReaction EngineeringEdited byTh. Meyer, J. KeurentjesHandbook of Polymer Reaction Engineering. Edited by T. Meyer, J. KeurentjesCopyright 8 2005 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 3-527-31014-2Further Titles of InterestE. S. Wilks (Ed.)Industrial Polymers HandbookProducts, Processes, Applications2000ISBN 3-527-30260-3H.-G. Elias (Ed.)MacromoleculesVols. 142005ISBN 3-527-31172-6, 3-527-31173-4, 3-527-31174-2,3-527-31175-0M. F. Kemmere, Th. Meyer (Eds.)Supercritical Carbon Dioxidein Polymer Reaction Engineering2005ISBN 3-527-31092-4M. Xanthos (Ed.)Functional Fillers for Plastics2005ISBN 3-527-31054-1R. C. Advincula, W. J. Brittain, K. C. Caster, J. Ru u he (Eds.)Polymer Brushes2004ISBN 3-527-31033-9H.-G. Elias (Ed.)An Introduction to PlasticsSecond, Completely Revised Edition2003ISBN 3-527-29602-6Handbook of Polymer Reaction EngineeringEdited byThierry Meyer, Jos KeurentjesEditorsDr. Thierry MeyerSwiss Federal Institute of TechnologyInstitute of Process ScienceEPFL, ISP-GPM1015 LausanneSwitzerlandProf. Jos T. F. KeurentjesProcess Development GroupEindhoven University of TechnologyP.O. Box 5135600 MB EindhovenThe Netherlands9 All books published by Wiley-VCH arecarefully produced. Nevertheless, authors,editors, and publisher do not warrant theinformation contained in these books,including this book, to be free of errors.Readers are advised to keep in mind thatstatements, data, illustrations, proceduraldetails or other items may inadvertently beinaccurate.Library of Congress Card No.: Applied forBritish Library Cataloging-in-PublicationData: A catalogue record for this book isavailable from the British LibraryBibliographic information published byDie Deutsche BibliothekDie Deutsche Bibliothek lists this publica-tion in the Deutsche Nationalbibliograe;detailed bibliographic data is available inthe Internet at hhttp://dnb.ddb.dei.8 2005 WILEY-VCH Verlag GmbH & Co.KGaA, WeinheimAll rights reserved (including those oftranslation into other languages). No part ofthis book may be reproduced in any form nor transmitted or translated into machinelanguage without written permissionfrom the publishers. Registered names,trademarks, etc. used in this book, evenwhen not specically marked as such, arenot to be considered unprotected by law.Printed in the Federal Republic of GermanyPrinted on acid-free paperComposition Asco Typesetters, Hong KongPrinting betz-druck gmbh, DarmstadtBookbinding Litges & Dopf BuchbindereiGmbH, HeppenheimISBN-13 978-3-527-31014-2ISBN-10 3-527-31014-2ForewordA principal dierence between science and engineering is intent. Science is usedto bring understanding and order to a specic object of study to build a body ofknowledge with truth and observable laws. Engineering is more applied and prac-tical, focused on using and exploiting scientic understanding and scientic prin-ciples to make products to benet mankind. A polymer reaction engineer seeks theapplied and practical as the title implies, but the path to success is most oftenthrough polymer science. This truth is steeped in history there are many exam-ples of polymeric products commercialized without adequate understanding of thechemistry and physics of the underlying polymerization. Polymer reaction engi-neers, faced with detriments in process safety, product quality or product cost, be-come the driving force behind many polymer science developments. As such, poly-mer reaction engineering is more a collaboration of polymer science and reactionengineering. A collaboration where polymer reaction engineers develop a rm un-derstanding of the many aspects of polymer chemistry and physics to successfullyapply chemical engineering principles to new product developments. Only throughthe integration of science and engineering are such products realized.This handbook is a testimony to this melding of polymer science and chemicalengineering that denes polymer reaction engineering. Thierry Meyer and JosKeurentjes have compiled a strong list of contributors with an even balance fromacademia and industry. The text oers a comprehensive view of polymer reactionengineering. The text starts with an overview describing the important integrationof science and engineering in polymer reaction engineering and ends with recentand potential breakthrough developments in polymer processing. The middlechapters are divided into three sections. The rst section is devoted to the scienceand chemistry of the major types of polymerization. Included are step and chaingrowth polymerizations with chapters devoted specically to several dierent chaingrowth methods. The central section of the middle chapters is dedicated to poly-mer reaction engineering tools and methods. The very important topics of safetyand process control are detailed and help frame the conditions through which suc-cessful scale-ups are achieved. The last section of the middle chapters is focused onthe physics and physical nature of formed polymers including their physical andmechanical structure. In these chapters, many of the processes that modify poly-Vmers through man-made and natural change are discussed. The details of polymerend use are also presented.This tome represents the rst published handbook on polymer reaction engi-neering and should be well received in academia and industry. Polymer reactionengineering became recognized as a separate engineering discipline in the 1970s.It is well past due that such a handbook be published. The broad scope and depthof coverage should make it an important reference for years to come.Michael C. Grady, ScDSenior Engineering AssociateDuPontPhiladelphia, PennsylvaniaVI ForewordContentsVolume 1Foreword VPreface XXIXList of Contributors XXXI1 Polymer Reaction Engineering, an Integrated Approach 1Th. Meyer and J. T. F. Keurentjes1.1 Polymer Materials 11.2 A Short History of Polymer Reaction Engineering 41.3 The Position of Polymer Reaction Engineering 51.4 Toward Integrated Polymer Reaction Engineering 71.5 The Disciplines in Polymer Reaction Engineering 91.5.1 Polymerization Mechanisms 111.5.2 Fundamental and Engineering Sciences 121.6 The Future: Product-inspired Polymer Reaction Engineering 141.7 Concluding Remarks 15References 152 Polymer Thermodynamics 17Theodoor W. de Loos2.1 Introduction 172.2 Thermodynamics and Phase Behavior of Polymer Solutions 182.2.1 Thermodynamic Principles of Phase Equilibria 182.2.2 Fugacity and Activity 182.2.3 Equilibrium Conditions 202.2.4 Low-pressure VaporLiquid Equilibria 212.2.5 FloryHuggins Theory and LiquidLiquid Equilibria 212.2.6 High-pressure LiquidLiquid and VaporLiquid Equilibria 252.3 Activity Coecient Models 292.3.1 FloryHuggins Theory 30VII2.3.2 Hansen Solubility Parameters 322.3.3 Correlation of Solvent Activities 342.3.4 Group Contribution Models 352.4 Equation of State Models 392.4.1 The SanchezLacombe Lattice Fluid Theory 402.4.2 Statistical Associating-uid Theory 442.4.2.1 SAFT and PC-SAFT Hard Chain Term 442.4.2.2 SAFT Dispersion Term 452.4.2.3 The PC-SAFT Dispersion Term 462.4.2.4 SAFT and PC-SAFT Applications 472.4.2.5 Extension to Copolymers 482.5 Conclusions 50Notation 52References 543 Polycondensation 57Mario Rui P. F. N. Costa and Rolf Bachmann3.1 Basic Concepts 573.1.1 A Brief History 573.1.2 Molecular Weight Growth and Carothers Equation 593.1.3 The Principle of Equal Reactivity and the Prediction of the Evolution ofFunctional Group Concentrations 623.1.4 Eect of Reaction Media on Equilibrium and Rate Parameters 623.1.5 Polycondensation Reactions with Substitution Eects 643.1.6 Exchange Reactions 663.1.7 Ring-forming Reactions 673.1.8 Modeling of Polymerization Schemes 683.2 Mass Transfer Issues in Polycondensations 693.2.1 Removal of Volatile By-products 693.2.2 Solid-state Polycondensation 803.2.3 Interfacial Polycondensation 823.3 Polycondensation Processes in Detail 853.3.1 Polyesters 853.3.1.1 Structure and Production Processes 853.3.1.2 Acid-catalyzed Esterication and Alcoholysis 863.3.1.3 Catalysis by Metallic Compounds 873.3.1.4 Side Reactions in Aromatic Polyester Production 893.3.1.5 Side Reactions in the Formation of Unsaturated Polyesters 903.3.1.6 Modeling of Processes of Aromatic Polyester Production 913.3.1.7 Modeling of Processes for Unsaturated Polyester Production 923.3.2 Polycarbonates 933.3.2.1 General Introduction 933.3.2.2 Interfacial Polycondensation 943.3.2.3 Melt Transesterication 963.3.3 Polyamides 98VIII Contents3.3.3.1 Introduction 983.3.3.2 Kinetic Modeling 983.3.3.3 Nonoxidative Thermal Degradation Reactions 1003.3.3.4 Process Modeling 1013.3.4 Polymerizations with Formaldehyde: Amino Resins (Urea andMelamine) and Phenolics 1023.3.4.1 Formaldehyde Solutions in Water 1023.3.4.2 Amino Resins 1023.3.4.3 Phenolic Resins 1073.3.5 Epoxy Resins 1083.3.6 Polyurethanes and Polyureas 1093.4 Modeling of Complex Polycondensation Reactions 1133.4.1 Overview 1133.4.2 Description of Reactions in Polycondensations of Several Monomerswith Substitution Eects 1133.4.3 Equilibrium Polycondensations with Several Monomers 1173.4.4 Kinetic Modeling of Irreversible Polycondensations 1293.4.5 Kinetic Modeling of Linear Reversible Polycondensations 133Notation 136References 1444 Free-radical Polymerization: Homogeneous 153Robin A. Hutchinson4.1 FRP Properties and Applications 1534.2 Chain Initiation 1544.3 Polymerization Mechanisms and Kinetics 1564.3.1 Homopolymerization 1574.3.1.1 Basic Mechanisms 1574.3.1.2 Kinetic Coecients 1614.3.1.3 Additional Mechanisms 1694.3.2 Copolymerization 1794.3.2.1 Basic Mechanisms 1794.3.2.2 Kinetic Coecients 1834.3.2.3 Additional Mechanisms 1874.3.3 Diusion-controlled Reactions 1904.4 Polymer Reaction Engineering 1934.4.1 Types of Industrial Reactors 1954.4.1.1 Batch Processes 1954.4.1.2 Semi-batch Processes 1964.4.1.3 Continuous Processes 1964.4.2 Mathematical Modeling of FRP Kinetics 1974.4.2.1 Method of Moments 1984.4.2.2 Modeling of Distributions 2014.4.3 Reactor Modeling 2034.4.3.1 Batch Polymerization 204Contents IX4.4.3.2 Continuous Polymerization 2044.4.3.3 Complex Flowsheets 2054.4.3.4 Computational Fluid Dynamics (CFD) 2054.4.3.5 Model-based Control 2064.5 Summary 206Notation 206References 2095 Free-radical Polymerization: Suspension 213B. W. Brooks5.1 Key Features of Suspension Polymerization 2135.1.1 Basic Ideas 2135.1.2 Essential Process Components 2145.1.3 Polymerization Kinetics 2145.1.4 FluidFluid Dispersions and Reactor Type 2155.1.5 Uses of Products from Suspension Polymerization 2165.2 Stability and Size Control of Drops 2165.2.1 Stabilizer Types 2175.2.2 Drop Breakage Mechanisms 2185.2.3 Drop Coalescence 2225.2.4 Drop Size Distributions 2235.2.5 Drop Mixing 2245.3 Events at High Monomer Conversion 2285.3.1 Breakage of Highly Viscous Drops 2295.3.2 Polymerization Kinetics in Viscous Drops 2295.3.3 Consequences of Polymer Precipitation Inside Drops 2305.4 Reaction Engineering for Suspension Polymerization 2345.4.1 Dispersion Maintenance and Reactor Choice 2345.4.2 Agitation and Heat Transfer in Suspensions 2355.4.3 Scaleup Limitations with Suspension Polymerization 2375.4.4 Reactor Safety with Suspension Processes 2385.4.5 Component Addition during Polymerization 2385.5 Inverse Suspension Polymerization 2395.5.1 Initiator Types 2395.5.2 Drop Mixing with Redox Initiators 2405.6 Future Developments 2405.6.1 Developing Startup Procedures for Batch and Semi-batch Reactors 2405.6.2 Maintaining Turbulence Uniformity in Batch Reactors 2425.6.3 Developing Viable Continuous-ow Processes 2425.6.4 Quantitative Allowance for the Eects of Changes in the Properties ofthe Continuous Phase 2425.6.5 Further Study of the Role of Secondary Suspending Agents 2435.6.6 Further Characterization of Stabilizers from Inorganic Powders 243Notation 243References 244X Contents6 Emulsion Polymerization 249Jose C. de la Cal, Jose R. Leiza, Jose M. Asua, Alessandro Butte`, Guiseppe Storti,and Massimo Morbidelli6.1 Introduction 2496.2 Features of Emulsion Polymerization 2506.2.1 Description of the Process 2506.2.2 Radical Compartmentalization 2546.2.3 Advantages of Emulsion Polymerization 2546.3 Alternative Polymerization Techniques 2566.4 Kinetics of Emulsion Polymerization 2586.4.1 Monomer Partitioning 2596.4.2 Average Number of Radicals per Particle 2606.4.3 Number of Polymer Particles 2646.4.3.1 Heterogeneous Nucleation 2646.4.3.2 Homogeneous Nucleation 2666.4.3.3 Simultaneous Heterogeneous and Homogeneous Nucleation 2676.4.3.4 Coagulative Nucleation 2676.5 Molecular Weights 2676.5.1 Linear Polymers 2686.5.1.1 ZeroOne System (SmithEwart Cases 1 and 2) 2686.5.1.2 Pseudo Bulk System (SmithEwart Case 3) 2706.5.2 Nonlinear Polymers: Branching, Crosslinking, and Gel Formation2726.6 Particle Morphology 2736.7 Living Polymerization in Emulsion 2756.7.1 Chemistry of LRP 2756.7.1.1 Nitroxide-mediated Polymerization (NMP) 2776.7.1.2 Atom-transfer Radical Polymerization (ATRP) 2776.7.1.3 Degenerative Transfer (DT) 2786.7.1.4 Reversible AdditionFragmentation Transfer (RAFT) Polymerization2796.7.2 Polymerization of LRP in Homogeneous Systems 2806.7.3 Kinetics of LRP in Heterogeneous Systems 2826.7.4 Application of LRP in Heterogeneous Systems 2846.7.4.1 Ab-initio Emulsion Polymerization 2846.7.4.2 Miniemulsion Polymerization 2856.8 Emulsion Polymerization Reactors 2866.8.1 Reactor Types and Processes 2866.8.1.1 Stirred-tank Reactors 2866.8.1.2 Tubular Reactors 2876.8.2 Reactor Equipment 2886.8.2.1 Mixing 2896.8.2.2 Heat Transfer 2906.9 Reaction Engineering 2906.9.1 Mass Balances 291Contents XI6.9.2 Heat Balance 2926.9.3 Polymer Particle Population Balance (Particle Size Distribution)2946.9.4 Scaleup 2956.10 On-line Monitoring in Emulsion Polymerization Reactors 2966.10.1 On-line Sensor Selection 2976.10.1.1 Latex Gas Chromatography 2986.10.1.2 Head-space Gas Chromatography 2986.10.1.3 Densimetry 2986.10.1.4 Ultrasound 2996.10.1.5 Spectroscopic Techniques 2996.10.1.6 Reaction Calorimetry 3026.11 Control of Emulsion Polymerization Reactors 305Notation 312References 3177 Ionic Polymerization 323Klaus-Dieter Hungenberg7.1 Introduction 3237.2 Anionic Polymerization 3257.2.1 Anionic Polymerization of Hydrocarbon Monomers LivingPolymerization 3267.2.1.1 Association Behavior/Kinetics 3267.2.1.2 Molecular Weight Distribution of Living Polymers 3317.2.1.3 Side Reactions 3367.2.1.4 Copolymerization 3387.2.1.5 Tailor-made Polymers by Living Polymerization Optimization 3417.2.1.6 Industrial Aspects Production of Living Polymers 3437.2.2 Anionic Polymerization of Vinyl Monomers Containing Heteroatoms3447.2.3 Anionic Polymerization of Monomers Containing Hetero Double Bonds3467.2.4 Anionic Polymerization via Ring Opening 3467.3 Cationic Polymerization 3517.3.1 Cationic Polymerization of Vinyl Monomers 3517.3.2 Cationic Ring-opening Polymerization 3537.4 Conclusion 356Notation 357References 3598 Coordination Polymerization 365Joao B. P. Soares and Leonardo C. Simon8.1 Polyolen Properties and Applications 3658.1.1 Introduction 3658.1.2 Types of Polyolens and Their Properties 366XII Contents8.1.3 The Importance of Proper Microstructural Determination and Controlin Polyolens 3698.2 Catalysts for Olen Polymerization 3728.2.1 ZieglerNatta, Phillips, and Vanadium Catalysts 3788.2.2 Metallocene Catalysts 3798.2.3 Late Transition Metal Catalysts 3818.3 Polymerization Kinetics and Mechanism with Coordination Catalysts3838.3.1 Comparison between Coordination and Free-radical Polymerization3838.3.2 Polymerization Kinetics with Single-site Catalysts 3838.3.2.1 Homopolymerization 3838.3.2.2 Copolymerization 3888.3.3 Polymerization Kinetics with Multiple-site Catalysts 3928.3.4 Long-chain Branch Formation 3958.4 Single Particle Models Mass- and Heat-transfer Resistances 3998.5 Macroscopic Reactor Modeling Population Balances and the Methodof Moments 4088.5.1 Homopolymerization 4088.5.2 Copolymerization 4138.6 Types of Industrial Reactors 4168.6.1 Gas-phase Reactors 4208.6.2 Slurry Reactors 4228.6.3 Solution Reactors 4238.6.4 Multizone Reactors 425Notation 425References 4289 Mathematical Methods 431P. D. Iedema and N. H. Kolhapure9.1 Introduction 4319.2 Discrete Galerkin hp Finite Element Method 4329.3 Method of Moments 4359.3.1 Introduction 4359.3.2 Linear Polymerization 4359.3.3 Nonlinear Polymerization 4389.4 Comparison of Galerkin-FEM and Method of Moments 4409.5 Classes Approach 4449.5.1 Introduction 4449.5.2 Computing the CLD of Poly(vinyl acetate) for a Maximum of One TDBper Chain 4449.5.3 Multiradicals in Radical Polymerization 4469.6 Pseudo-distribution Approach 4499.6.1 Introduction 4499.6.2 CLD/DBD for Mixed-metallocene Polymerization of Ethylene 451Contents XIII9.6.2.1 Formulation of Pseudo-distribution Problem 4519.6.2.2 Construction of the Full 2D Distribution 4569.6.3 CLD/Number of Terminal Double Bonds (TDB) Distribution forPoly(vinyl acetate) More than one TDB per Chain 4589.6.3.1 General Case 4589.6.3.2 TDB Pseudo-distribution Approach for a Maximum of one TDB perChain 4669.6.3.3 TDB Pseudo-distribution Approach for More than one TDB per Chain4679.6.4 Radical Polymerization of Ethylene to Low-density Polyethylene (LDPE)4699.6.4.1 Introduction 4699.6.5 Radical Copolymerization 4739.6.5.1 Introduction 4739.6.5.2 Balance Equations 4749.7 Probability Generating Functions 4809.7.1 Introduction 4809.7.2 Probability Generating Functions in a Transformation Method 4809.7.3 Probability Generating Functions and Cascade Theory 4819.8 Monte Carlo Simulations 4859.8.1 Introduction 4859.8.2 Weight-fraction Sampling of Primary Polymers: Batch Reactor,Transfer to Polymer 4869.8.3 Example 4909.8.4 CSTR with Transfer to Polymer 4919.8.5 Comparison of Galerkin-FEM Classes Model and CSTR with Transferto Polymer 4929.8.6 Batch Reactor, Terminal Double Bond Incorporation 4939.8.7 CSTR, Terminal Double Bond Incorporation 4979.8.8 Incorporation of Recombination Termination 4989.8.9 Incorporation of Random Scission, Linear Chains, Batch Reactor 4989.8.10 Combined Scission/Branching 5019.8.11 Scission in a CSTR 5019.9 Prediction of Branched Architectures by Conditional Monte CarloSampling 5029.9.1 Introduction 5029.9.2 Branched Architectures from Radical Polymerization in a CSTR 5039.9.3 Branched Architectures from Polymerization of Olens with Singleand Mixed Branch-forming Metallocene Catalysts in a CSTR 5059.9.3.1 Introduction 5059.9.3.2 Single-catalyst System 5059.9.3.3 Synthesis of Topology 5059.9.3.4 Mixed-catalyst System 5089.9.4 Mathematical Methods for Characterization of Branched Architectures5109.9.4.1 Graph Theoretical Connectivity Matrices 510XIV Contents9.9.4.2 Characterization of Architectures by Radius of Gyration 5119.9.4.3 Characterization of Architectures by Seniorities and Priorities 5129.10 Computational Fluid Dynamics for Polymerization Reactors 5179.10.1 Introduction 5179.10.1.1 Modeling Challenges 5179.10.2 Development and Optimization of Modern Polymerization Reactors5189.10.2.1 Benets of CFD 5199.10.2.2 Limitations of CFD 5199.10.3 Integration of CFD with Polymerization Kinetics 5209.10.3.1 Classication and Complexity of CFD Models 5219.10.3.2 Treatment of Polymerization Kinetics 5229.10.3.3 Illustration of Homogeneous Reactor Model Formulation 5229.10.4 Target Applications 5239.10.4.1 Illustrative Case Studies 5239.10.5 Concluding Remarks 528Acknowledgments 530References 53010 Scaleup of Polymerization Processes 533E. Bruce Nauman10.1 Historic and Economic Perspective 53310.2 The Limits of Scale 53310.3 Scaleup Goals 53410.4 General Approaches 53510.5 Scaleup Factors 53710.6 Stirred-tank Reactors 53710.7 Design Considerations for Stirred Tanks 54110.8 Multiphase Stirred Tanks 54210.9 Stirred Tanks in Series 54210.10 Tubular Reactors 54310.11 Static Mixers 54510.12 Design Considerations for Tubular Reactors 54610.13 Extruder and Extruder-like Reactors 54910.14 Casting Systems 54910.15 Concluding Remarks 550Notation 550References 551Volume 211 Safety of Polymerization Processes 553Francis Stoessel11.1 Introduction 55311.2 Principles of Chemical Reactor Safety Applied to Polymerization 55411.2.1 Cooling Failure Scenario 554Contents XV11.2.2 Criticality Classes Applied to Polymerization Reactors 55711.2.2.1 Description of the Criticality Classes 55811.2.3 Heat Balance of Reactors 55911.2.3.1 Heat Production 55911.2.3.2 Heat Exchange 56011.2.3.3 Heat Accumulation 56111.2.3.4 Convective Heat Transport due to Feed 56111.2.3.5 Stirrer 56111.2.3.6 Heat Losses 56211.2.3.7 Simplied Expression of the Heat Balance 56211.2.4 Dynamic Control of Reactors 56211.2.5 Thermal Stability of Polymerization Reaction Masses 56311.3 Specic Safety Aspects of Polymerization Reactions 56411.3.1 Kinetic Aspects 56411.3.2 Thermochemical Aspects 56511.3.3 Factors Leading to Changing Heat Release Rates 56811.4 Cooling of Polymerization Reactors 57011.4.1 Indirect Cooling: Heat Exchange Across the Reactor Wall 57011.4.2 Hot Cooling: Cooling by Evaporation 57411.4.3 Importance of the Viscosity 57811.5 Chemical Engineering for the Safety of Polymerization Processes57911.5.1 Batch Processes 57911.5.2 Semi-batch Processes 58011.5.2.1 Initiation 58111.5.2.2 Feed 58211.5.2.3 Final Stage 58311.5.2.4 Practical Aspects 58311.5.3 Continuous Processes 58411.5.3.1 Concentration Stability 58411.5.3.2 Particle Number Stability 58411.5.4 Design Measures for Safety 58511.5.4.1 Process Design 58611.5.4.2 Reactor Design 58611.5.4.3 Control of Feed 58711.5.4.4 Emergency Cooling 58711.5.4.5 Inhibition 58811.5.4.6 Quenching 58811.5.4.7 Dumping 58811.5.4.8 Controlled Depressurization 58811.5.4.9 Pressure Relief 58811.5.4.10 Time Factor 58911.6 Conclusion 589References 590Notation 591XVI Contents12 Measurement and Control of Polymerization Reactors 595John R. Richards and John P. Congalidis12.1 Introduction 59512.1.1 Denitions 59512.1.2 Measurement Error 59712.2 Measurement Techniques 59812.2.1 Temperature 59912.2.1.1 Resistance Thermometers 59912.2.1.2 Thermocouples 60012.2.1.3 Expansion Thermometers 60112.2.1.4 Radiation Pyrometers 60112.2.2 Pressure Measurement 60212.2.3 Weight 60412.2.4 Liquid Level 60512.2.5 Flow 60812.2.6 Densitometry, Dilatometery, and Gravimetry 61712.2.7 Viscosity 61912.2.8 Composition 62012.2.9 Surface Tension 62212.2.10 Molecular Weight Distribution (MWD) 62212.2.11 Particle Size Distribution (PSD) 62312.3 Sensor Signal Processing 62512.3.1 Sensors and Transmitters 62512.3.2 Converters 62612.3.3 Indicators 62612.3.4 Filtering Techniques 62712.4 Regulatory Control Engineering 62712.4.1 General 62712.4.2 Process Dynamics 63012.4.2.1 First-order System 63112.4.2.2 Second-order System 63212.4.2.3 High-order and Dead Time Systems 63612.4.2.4 First-order Plus Dead Time System 63612.4.2.5 Integrating System 63812.4.2.6 Integrator plus Dead Time System 63912.4.3 Controllers 63912.4.3.1 Proportional Control 64012.4.3.2 Integral Control 64112.4.3.3 Derivative Control 64112.4.3.4 PI, PD, and PID Control 64212.4.3.5 Digital Controllers 64212.4.3.6 Controller Tuning 64412.4.3.7 OnO Controllers 64612.4.3.8 Self-operated Regulators 64712.4.4 Valve Position Controllers 650Contents XVII12.4.5 Single-loop Controllers 65012.4.6 Digital Control Systems 65012.4.7 Actuators 65212.5 Advanced Control Engineering 65612.5.1 Feedforward Control 65912.5.1.1 Steady-state Model Feedforward Control 66012.5.1.2 Ratio Control 66012.5.2 Cascade Control 66112.5.3 FeedforwardFeedback Control 66312.5.4 State Estimation Techniques 66612.5.5 Model Predictive Control 66812.5.6 Batch and Semi-batch Control 66912.5.6.1 Operation and Variability 66912.5.6.2 Statistical Process Control 67112.5.7 Future Trends 671Notation 672References 67513 Polymer Properties through Structure 679Uday Shankar Agarwal13.1 Thermal Properties of Polymers 67913.1.1 Crystalline and Amorphous Polymers 68013.1.2 Inuence of Polymer Structure on Crystallizability of Polymers 68213.1.3 The Glass Transition Temperature 68313.1.4 Inuence of Polymer Structure on Tg of Polymers 68413.1.5 The Crystallization Temperature and the Melting Point 68613.1.6 Tuning Polymer Crystallization for Properties 68613.1.7 Morphology of Crystalline Polymers 68813.1.8 Tailoring Polymer Properties through Modication, Additives, andReinforcement 69013.1.8.1 New Morphologies through Block Copolymers 69113.1.8.2 Polymeric Nanocomposites 69213.2 Polymer Conformation and Related Properties 69213.2.1 The Chain Conformation 69213.2.2 Solubility of Polymers 69413.2.3 Dilute Solution Zero-shear Viscosity 69513.2.3.1 Polymers as Dumbbells 69613.2.3.2 Polymers as Chains of Beads and Springs 69713.2.4 Viscosity of Concentrated Solutions and Melts 69813.2.5 Nonlinear Polymers 69913.2.6 Rigid Rod-like Polymers 70113.3 Polymer Rheology 70213.3.1 The Viscous Response: Shear Thinning 70213.3.2 Normal Stresses during Shear Flow 70313.3.3 Extensional Thickening 705XVIII Contents13.3.4 The Elastic Response 70613.3.4.1 Ideal Elastic Response 70613.3.4.2 Rubberlike Elasticity 70613.3.5 The Viscoelastic Response 70713.3.5.1 Linear Viscoelasticity in Dynamic Oscillatory Flow 70913.3.6 Inuence of Polymer Branching Architecture in Bulk Polymers 71113.3.7 Polymers as Rheology Modiers 71213.3.8 Rheological Control with Block Copolymers 71413.3.9 Polymer-like Structures through Noncovalent Associations 71513.4 Summary 715Notation 716References 71814 Polymer Mechanical Properties 721Christopher J. G. Plummer14.1 Introduction 72114.1.1 Long-chain Molecules 72114.1.2 Simple Statistical Descriptions of Long-chain Molecules 72214.2 Elasticity 72414.2.1 Deformation of an Elastic Solid 72414.2.2 Thermodynamics of Rubber Elasticity 72514.2.3 Statistical Mechanical Approach to Rubber Elasticity 72714.3 Viscoelasticity 72914.3.1 Linear Viscoelasticity 72914.3.2 TimeTemperature Superposition 73414.3.3 Molecular Models for Polymer Dynamics 73614.3.4 Nonlinear Viscoelasticity 74014.4 Yield and Fracture 74114.4.1 Yield in Polymers 74114.4.2 Models for Yield 74414.4.3 Semicrystalline Polymers 74614.4.4 Crazing and Fracture 74814.5 Conclusion 752References 75515 Polymer Degradation and Stabilization 757Tuan Quoc Nguyen15.1 Introduction 75715.2 General Features of Polymer Degradation 75915.2.1 Degradative Reactions 75915.2.1.1 Initiation 76015.2.1.2 Propagation 76015.2.1.3 Chain Branching 76115.2.1.4 Termination 76215.2.2 Some Nonradical Degradation Mechanisms 763Contents XIX15.2.3 Physical Factors 76315.2.3.1 Glass Transition Temperature 76415.2.3.2 Polymer Morphology 76615.3 Degradation Detection Methods 76715.3.1 Mechanical Tests 76815.3.2 Gel Permeation Chromatography 77115.3.3 Fourier Transform Infrared Spectroscopy 77315.3.4 Magnetic Resonance Spectroscopy 77515.3.4.1 Nuclear Magnetic Resonance (NMR) 77515.3.4.2 Electron Spin Resonance (ESR) 77615.3.5 Oxygen Uptake 77615.3.6 Chemiluminescence 77815.4 Thermal Degradation 77815.4.1 Thermal Stability 77915.4.2 Polymer Structure and Thermal Stability 77915.4.3 Computer Simulation 78015.4.4 Thermal Oxidative Degradation of Polypropylene 78215.4.4.1 Initiation 78215.4.4.2 Propagation 78415.4.4.3 Chain Branching 78515.4.4.4 Termination 78615.4.4.5 Secondary Reactions 78615.4.4.6 Formation of Volatile Compounds 78815.4.5 Homogeneous versus Heterogeneous Kinetics 78915.4.6 Applications of Thermal Degradation 79015.4.6.1 Analytical Pyrolysis 79015.4.6.2 Introduction of New Chemical Functionalities 79115.4.6.3 Chemical Modication of Polymer Structure 79115.4.6.4 Metal Injection Molding (MIM) 79215.4.6.5 Recycling 79215.5 Photodegradation 79315.5.1 Absorption of UV Radiation by Polymers 79315.5.2 The Solar Spectrum 79615.5.3 Photo-oxidation Prole 79615.5.4 Inuence of Wavelength: the Activation and Action Spectrum 79915.5.5 Photodegradation Mechanisms 80215.5.5.1 Photoinitiation 80215.5.5.2 The Norrish Photoprocesses 80315.5.5.3 Photo-Fries Rearrangement 80315.6 Radiolytic Degradation 80515.6.1 Interaction of High-energy Radiation with Matter 80515.6.2 Radiation Chemistry 80715.6.3 Radiolysis Stabilization 81015.6.4 Applications 81115.6.4.1 Radiation Sterilization 812XX Contents15.6.4.2 Controlled Degradation and Crosslinking 81215.7 Mechanochemical Degradation 81315.7.1 Initiation by Mechanical Stresses 81315.7.1.1 Eect of Tensile Stress on Chemical Reactivity 81315.7.1.2 Breaking Strength of a Covalent Bond 81415.7.1.3 Rate of Stress-activated Chain Scission 81515.7.2 Extrusion Degradation 81615.7.3 Applications 81715.8 Control and Prevention of Aging of Plastic Materials 81815.8.1 Antioxidants 81815.8.1.1 Radical Antioxidants 81815.8.1.2 Hindered Amine Stabilizers (HAS) 81915.8.1.3 Peroxide Decomposers 82115.8.2 Photostabilizers 82215.8.3 PVC Heat Stabilizers 82315.8.4 Other Classes of Stabilizers 82415.8.4.1 Metal Deactivators 82415.8.4.2 Antiozonants 82415.9 Lifetime Prediction 82415.10 Conclusions 826Notation 827References 83016 Thermosets 833Rolf A. T. M. van Benthem, Lars J. Evers, Jo Mattheij, Ad Hoand, Leendert J.Molhoek, Ad J. de Koning, Johan F. G. A. Jansen, and Martin van Duin16.1 Introduction 83316.1.1 Thermoset Materials 83316.1.2 Networks 83416.1.3 Advantages 83516.1.4 Curing Resins 83516.1.5 Functionality 83516.1.6 Formulation 83616.1.7 Production 83716.1.8 General Areas of Application 83716.2 Phenolic Resins 83816.2.1 Introduction 83816.2.2 Chemistry 83816.2.2.1 Resols 84016.2.2.2 Novolacs 84016.2.2.3 Epoxy-novolacs 84116.2.2.4 Discoloration 84116.2.3 Production 84216.2.4 Properties and Applications 84216.3 Amino Resins 843Contents XXI16.3.1 Introduction 84316.3.2 Chemistry 84316.3.2.1 Polymerization Chemistry 84516.3.3 Production 84816.3.4 Properties and Applications 84916.4 Epoxy Resins 84916.4.1 Introduction 84916.4.2 Chemistry 85016.4.2.1 Cure 85116.4.3 Production 85316.4.3.1 Standard Liquid 85316.4.3.2 Tay Process 85416.4.3.3 Advancement Process 85416.4.4 Properties and Applications 85516.5 Alkyd Resins 85516.5.1 Introduction 85516.5.2 Chemistry 85616.5.2.1 The Alkyd Constant 85816.5.2.2 Autoxidative Drying 85816.5.3 Production 85916.5.4 Properties and Applications 86116.5.4.1 Short Oil Alkyds 86116.5.4.2 Long Oil Alkyds 86116.5.4.3 Medium Oil Alkyds 86116.5.5 Alkyd Emulsions 86116.5.5.1 The Inversion Process 86216.6 Saturated Polyester Resins 86216.6.1 Introduction 86216.6.2 Chemistry 86316.6.3 Production 86516.6.3.1 Monitoring the Reaction 86516.6.4 Properties and Applications 86616.6.5 Powder Coatings 86616.6.5.1 Application 86716.6.5.2 Crosslinking 86816.6.5.3 Advantages 86916.7 Unsaturated Polyester Resins and Composites 86916.7.1 Introduction 86916.7.2 Chemistry 86916.7.2.1 Crosslinking 87116.7.2.2 Styrene Emission 87116.7.2.3 Vinyl Ester Resins 87316.7.3 Production 87416.7.4 Reinforcement 87516.7.5 Fillers 878XXII Contents16.7.6 Processing 87916.7.6.1 Hand Lay-up and Spray-up 88216.7.6.2 Continuous Lamination 88216.7.6.3 Filament Winding 88216.7.6.4 Centrifugal Casting 88216.7.6.5 Pultrusion 88316.7.6.6 Cold-press Molding 88316.7.6.7 Resin Infusion 88316.7.6.8 Resin-transfer Molding 88316.7.6.9 Hot-press Molding 88316.7.6.10 Casting, Encapsulation, and Coating (Non-reinforced Applications)88616.7.7 Design Considerations: Mechanical Properties of Composites 88616.8 Acrylate Resins and UV Curing 88916.8.1 Introduction 88916.8.2 Chemistry 89016.8.3 Production 89116.8.3.1 Epoxy Acrylates 89116.8.3.2 Polyester Acrylates 89116.8.3.3 Urethane Acrylates 89216.8.3.4 Inside-out 89316.8.3.5 Outside-in 89416.8.3.6 Comparing Inside-out with Outside-in 89416.8.3.7 Stabilization 89416.8.3.8 Dilution 89516.8.3.9 Safety 89516.8.4 Properties 89516.8.5 Introduction to UV Curing 89616.8.5.1 General Introduction to UV-initiated Radical Polymerization 89616.8.5.2 Photoinitiators for Radical Polymerization 89716.8.5.3 Resin 89716.8.5.4 Reactive Diluent 89816.8.5.5 Curing Process 89916.8.5.6 Cationic Curing 90016.8.5.7 Base-mediated Curing 90116.9 Rubber 90116.9.1 Introduction 90116.9.1.1 Types of Rubber 90216.9.2 Polymerization 90316.9.3 Crosslinking 90416.9.3.1 Sulfur Vulcanization 90416.9.3.2 Peroxide Curing 90516.9.3.3 Processing 90616.9.4 Properties and Applications 90716.9.4.1 Advantages and Disadvantages 907Contents XXIII16.9.4.2 Thermoplastic Vulcanizates 907Notation 908References 90917 Fibers 911J. A. Juijn17.1 Introduction 91117.1.1 A Fiber World 91117.1.2 Scope of this Chapter 91217.2 Fiber Terminology 91217.2.1 Denitions: Fibers, Filaments, Spinning 91217.2.2 Synthetic Yarns 91417.2.3 Titer: Tex and Denier 91417.2.4 Tenacity and Modulus: g denierC1, N texC1, or GPa 91517.2.5 Yarn Appearance 91617.2.6 Textile, Carpet, and Industrial Yarns 91717.2.7 Physical Structure 91817.3 Fiber Polymers: Choice of Spinning Process 92017.3.1 Polymer Requirements 92017.3.2 Selection of Spinning Process 92017.3.3 Spinnability 92217.4 Melt Spinning 92317.4.1 Extrusion 92317.4.2 Polymer Lines and Spin-box 92417.4.3 Spinning Pumps 92517.4.4 Spinning Assembly 92617.4.4.1 Filtration 92617.4.4.2 Spinning Plate 92617.4.5 Quenching 92817.4.6 Finish 92917.4.7 Spinning Speed 93117.4.8 Winding 93117.4.9 Drawing 93117.4.10 Relaxation and Stabilization 93417.4.11 Process Integration 93417.4.12 Rheology 93417.4.12.1 Shear Viscosity 93417.4.12.2 Elasticity 93617.4.12.3 Elongational Viscosity 93617.4.13 Process Calculations 93617.4.13.1 Mass Flow 93717.4.13.2 Volume Flow 93717.4.13.3 Extrusion Speed and Elongation in the Spin-line 93717.4.13.4 Pressure Drop over the Spinning Holes 938XXIV Contents17.4.14 Polyester (Poly(ethylene terephthalate), PET) 93817.4.14.1 PET Polymer 93817.4.14.2 Spinning of PET 93917.4.14.3 PET Staple Fiber 93917.4.14.4 PET Textile Filament Yarns 94017.4.14.5 PET Industrial Yarns 94017.4.15 Polyamide (PA6 and PA66) 94117.4.15.1 PA Polymer 94117.4.15.2 PA Spinning 94117.4.15.3 PA Staple Fiber 94217.4.15.4 PA Textile Filament Yarns 94217.4.15.5 PA Industrial Yarns 94217.4.16 Polypropylene (PP) 94317.4.16.1 PP Polymer 94317.4.16.2 PP Spinning 94317.4.16.3 PP Staple Fiber 94317.4.16.4 PP Split Fiber 94317.4.16.5 PP Filament Yarns 94417.5 Solution Spinning 94417.5.1 Preparation of Spinning Dope 94417.5.2 Dry Spinning 94417.5.2.1 Cellulose Acetate 94517.5.2.2 Acrylics 94617.5.2.3 Poly(vinyl alcohol) 94617.5.3 Wet Spinning 94617.5.3.1 Viscose Rayon 94817.5.3.2 Acrylics 95117.5.3.3 Poly(vinyl alcohol) 95217.6 Comparison of Melt and Solution Spinning 95317.7 High-modulus, High-strength Fibers 95617.7.1 Air-gap Spinning 95617.7.1.1 Aramids 95617.7.1.2 Other Liquid-crystalline Polymers 96017.7.2 Gel Spinning 96117.7.2.1 Theory 96117.7.2.2 Gel Spinning of Polyethylene 96217.7.2.3 Other Gel-spun or Superdrawn Fibers 96417.7.3 Carbon Fiber 96517.7.3.1 Carbon Fiber from PAN 96517.7.3.2 Carbon Fiber from Pitch 96617.7.3.3 Applications of Carbon Fibers 96617.7.4 Other Advanced Fibers 966Notation 967Acknowledgments 969References 969Contents XXV18 Removal of Monomers and VOCs from Polymers 971Mar a J. Barandiaran and Jose M. Asua18.1 Introduction 97118.2 Polymer Melts and Solutions 97218.2.1 Devolatilization 97318.2.1.1 Fundamentals 97318.2.1.2 Implementation of Devolatilization 97518.2.1.3 Equipment 97518.3 Polyolens 97918.4 Waterborne Dispersions 97918.4.1 Post-polymerization 98018.4.1.1 Modeling Post-polymerization 98118.4.2 Devolatilization 98118.4.2.1 Modeling 98218.4.2.2 Rate-limiting Steps 98518.4.2.3 Devolatilization under Equilibrium Conditions 98618.4.2.4 Equipment 98618.4.3 Combined Processes 98818.4.4 Alternative Processes 98918.5 Summary 989Notation 990References 99119 Nano- and Microstructuring of Polymers 995Christiane de Witz, Carlos Sanchez, Cees Bastiaansen, and Dirk J. Broer19.1 Introduction 99519.1.1 Patterning Techniques 99619.1.2 Photoembossing 99819.2 Materials and their Photoresponsive Behavior 99919.3 Single-exposure Photoembossing 100119.4 Dual-exposure Photoembossing 100719.5 Complex Surface Structures from Interfering UV Laser Beams 100719.6 Surface Structure Development under Fluids 101019.7 Conclusion 1012Acknowledgments 1012Notation 1013References 101320 Chemical Analysis for Polymer Engineers 1015Peter Schoenmakers and Petra Aarnoutse20.1 Introduction 101520.2 Process Analysis 101720.2.1 Near-infrared Spectroscopy 101720.2.2 In-situ Raman Spectroscopy 101820.2.3 At-line Conversion Measurements 1020XXVI Contents20.3 Polymer Analysis 102220.3.1 Basic Laboratory Measurements 102220.3.1.1 Conversion 102220.3.2 Detailed Molecular Analysis 102320.3.2.1 FTIR Spectroscopy 102320.3.2.2 NMR Spectroscopy 102420.3.2.3 Mass Spectrometry 102520.3.3 Polymer Distributions 103020.3.3.1 Molecular Weight Distributions 103020.3.3.2 Functionality-type Distributions 103420.3.3.3 Chemical Composition Distributions (CCDs) 103720.3.3.4 Degree of Branching Distributions 104020.3.3.5 Complex Polymers (Multiple Distributions) 1041Notation 1044References 104521 Recent Developments in Polymer Processes 1047Maartje Kemmere21.1 Introduction 104721.2 Polymer Processes in Supercritical Carbon Dioxide 104821.2.1 Interactions of Carbon Dioxide with Polymers and Monomers 105021.2.1.1 Solubility in Carbon Dioxide 105121.2.1.2 Sorption and Swelling of Polymers 105221.2.1.3 Phase Behavior of MonomerPolymerCarbon Dioxide Systems 105421.2.2 Polymerization Processes in Supercritical Carbon Dioxide 105521.2.3 Polymer Processing in Supercritical Carbon Dioxide 105821.2.3.1 Extraction 106021.2.3.2 Impregnation and Dyeing 106121.3 Ultrasound-induced Radical Polymerization 106221.3.1 Ultrasound and Cavitation in Liquids 106321.3.2 Radical Formation by Cavitation 106521.3.3 Cavitation-induced Polymerization 106721.3.3.1 Bulk Polymerization 106721.3.3.2 Precipitation Polymerization 106921.3.3.3 Emulsion Polymerization 107021.3.4 Cavitation-induced Polymer Scission 107221.3.5 Synthesis of Block Copolymers 107321.4 Concluding Remarks and Outlook for the Future 1074Acknowledgments 1076Notation 1076References 1077Index 1083Contents XXVIIPrefaceFreshly started as chairman and secretary of the Working Party on Polymer Reac-tion Engineering it never crossed our mind to edit a book on this subject. Thischanged when Wiley-VCH asked if the working party would be able to provide atranslation of the Handbuch der Technischen Polymerchemie, written in 1993 byAdolf Echte. We decided to do so, but not exactly. Very rapidly we were convincedthat we needed a completely new book, covering the eld of polymer reaction engi-neering in a modern, broad and multidisciplinary approach. Many of the workingparty members directly agreed to participate, others needed somewhat strongerpersuasion techniques, and for some chapters we hired authors from other in-stitutions. In June 2003 we had completed the list of contributors, coming fromEurope, Canada and the USA. Now, roughly one year later, the new handbook isthere.The quality an edited book like this very much depends on the quality of the in-dividual contributions. It has been a great pleasure for us to see that all authorshave taken their writing jobs very seriously. With these contributions, we are surethat this book represents the state of the art in polymer reaction engineering. Itis intended to attract equally readers that are new in the eld as well as readersthat may be considered expert in some of the topics but want to broaden theirknowledge. We are convinced that the multidisciplinary and synergetic approachpresented in this book may act as an eye-opener for research and development ac-tivities going on in strongly related areas. We hope the reader will take advantageof this approach, where the references given in the various chapters may be a start-ing point for further reading.Reading books, you often read the preface as well. We have seen numerous ex-amples from which the frustration is quite obvious. Of course things may not al-ways work out the way you plan, that has also been the case for this book. Maybewe were just lucky, but we have greatly enjoyed doing this. Editing this book hasalso been a starting point for the editors to become friends, including Swiss cheesefondue and Dutch Friese nagelkaastaart in a friendly home setting. From thatperspective also Francine and Maartje have had their part both of the workloadbut also of the fun of all this.Finally, we would like to thank Karin Sora and Renate Doetzer from Wiley-VCHXXIXfor their help with the editing process. They really know to nd the balance be-tween waiting and pushing in order not to diverge too far from the schedule.Lausanne & Eindhoven, fall 2004Thierry Meyer & Jos KeurentjesXXX PrefaceList of ContributorsP. AarnoutsePolymer-Analysis GroupDepartment of Chemical Engineering(ITS)Faculty of Science, University ofAmsterdamNieuwe Achtergracht 1661018 WV AmsterdamThe NetherlandsDr. U. S. AgarwalPolymer Technology GroupDepartment of Chemical Engineeringand ChemistryEindhoven University of TechnologyP.O. Box 5135600 MB EindhovenThe NetherlandsProf. J. M. AsuaThe University of the Basque CountryInstitute for Polymer Materials(POLYMAT)Paseo Manuel Lardizabal 320018 Donostia-San SebastianSpainDr. R. BachmannBayer AGZT-TE-SVT51368 LeverkusenGermanyProf. M. J. BarandiaranThe University of the Basque CountryInstitute for Polymer Materials(POLYMAT)Manuel Lardizabal, 320018 Donostia-San SebastianSpainDr. C. W. M. BastiaansenEindhoven University of TechnologyDen Dolech 25600 MB EindhovenThe NetherlandsProf. D. J. BroerPhilips Research LaboratoriesProf. Holstlaan 45656 AA EindhovenThe NetherlandsandEindhoven University of TechnologyDen Dolech 25600 MB EindhovenThe NetherlandsandDutch Polymer Institute (DPI)P.O. Box 9025600 AX EindhovenThe NetherlandsXXXIPolymer TechnologyDepartment of Chemical Engineeringand ChemistryEindhoven University of TechnologyP.O. Box 5135600 MB EindhovenThe NetherlandsProf. B. W. BrooksLoughborough UniversityDepartment of ChemicalEngineeringLoughboroughLeicestershire, LE11 3TUUnited KingdomDr. A. Butte`Swiss Federal Institute ofTechnologyZurich, ETHZInstitut fur Chemie- undBioingenieurwissenschatenGruppe MorbidelliETH Hoenggerberg/HCI F1358093 ZurichSwitzerlandDr. J. P. CongalidisE.I. du Pont de Nemours andCompanyDuPont Central Research andDevelopmentExperimental StationWilmington, DE 19880USADr. M. R. P. F. N. CostaFaculty of EngineeringUniversity of PortoRua Roberto Frias, s/n4200-465 PortoPortugalProf. J. C. de la CalThe University of the Basque CountryInstitute for Polymer Materials(POLYMAT)Paseo Manuel Lardizabal, 320018 Donostia-San SebastianSpainDr. A. J. de KoningDSM ResearchOude Postbaan 16167 RG GeleenThe NetherlandsDr. T. W. de LoosDelft University of TechnologyFaculty of Applied SciencesDepartment Chemical TechnologyJulianalaan 1362628 BL DelftThe NetherlandsC. de WitzPhilips Research LaboratoriesProf. Holstlaan 45656 AA EindhovenThe NetherlandsDr. L. J. EversDSM MelamineOude Postbaan 16167 RG GeleenThe NetherlandsDr. A. HoandDSM Coating ResinsCeintuurbaan 58022 AW ZwolleThe NetherlandsDr. K.-D. HungenbergBASF AGPolymer Technology, B167056 LudwigshafenGermanyXXXII List of ContributorsProf. R. A. HutchinsonDepartment of Chemical EngineeringQueens UniversityDupuis Hall, 19 Division St.Kingston, Ontario K7M 2G9CanadaDr. P. D. IedemaDepartment of Chemical EngineeringUniversity of AmsterdamNieuwe Achtergracht 1661018 WV AmsterdamThe NetherlandsDr. J. F. G. A. JansenDSM ResearchOude Postbaan 16167 RG GeleenThe NetherlandsDr. J. A. JuijnResearch InstituteDepartment QRIP.O. Box 96006800 TC ArnheimThe NetherlandsDr. M. F. KemmereProcess Development GroupDepartment of Chemical Engineeringand ChemistryEindhoven University of TechnologyP.O. Box 5135600 MB EindhovenThe NetherlandsProf. J. T. F. KeurentjesProcess Development GroupEindhoven University of TechnologyP.O. Box 5135600 MB EindhovenThe NetherlandsN. H. KolhapureDuPont Engineering Research andTechnology1007 N. Market St.Wilmington, DE 19898-0001USAProf. J. R. LeizaThe University of the Basque CountryInstitute for Polymer Materials(POLYMAT)Paseo Manuel Lardizabal 320018 Donostia-San SebastianSpainJ. MattheijDSM MelamineOude Postbaan 16167 RG GeleenThe NetherlandsDr. T. MeyerSwiss Federal Institute of TechnologyInstitute of Process ScienceEPFL, ISP-GPM1015 LausanneSwitzerlandL. J. MolhoekDSM Coating ResinsCeintuurbaan 58022 AW ZwolleThe NetherlandsProf. M. MorbidelliSwiss Federal Institute of TechnologyZurich, ETHZInstitut fur Chemie- undBioingenieurwissenschaftenGruppe MorbidelliETH Hoenggerberg/HCI F1358093 ZurichSwitzerlandList of Contributors XXXIIIProf. E. B. NaumanThe Isermann Department of Chemicaland Biological EngineeringRensselaer Polytechnic InstituteTroy, NY 12180USADr. Q. T. NguyenLaboratory of Polymers (LP)Ecole Polytechnique Federalede Lausanne1015 LausanneSwitzerlandJ. C. PlummerLaboratory of Composite and PolymerTechnology (LTC)Ecole Polytechnique Federalede Lausanne1015 LausanneSwitzerlandDr. J. R. RichardsE. I. du pont de Nemours and CompanyDuPont Engineering and ResearchTechnologyExperimental StationWilmington, DE 19880USADr. C. SanchezEindhoven University of TechnologyDen Dolech 25600 MB EindhovenThe NetherlandsandDutch Polymer Institute (DPI)P.O. Box 9025600 AX EindhovenThe NetherlandsProf. P. J. SchoenmakersPolymer-Analysis GroupDepartment of Chemical Engineering(ITS)Faculty of Science, University ofAmsterdamNieuwe Achtergracht 1661018 WV AmsterdamThe NetherlandsProf. L. C. SimonDepartment of Chemical EngineeringUniversity of Waterloo200 University Avenue WestWaterloo, Ontario N2L 3G1CanadaProf. J. B. P. SoaresDepartment of Chemical EngineeringUniversity of Waterloo200 University Avenue WestWaterloo, Ontario N2L 3G1CanadaProf. F. StoesselSwiss Institute for the Promotion ofSafety and SecurityChemical Process Safety ConsultingKlybeckstrasse 141WKL-32.3224002 BaselSwitzerlandProf. G. StortiSwiss Federal Institute of TechnologyZurich, ETHZInstitut fur Chemie- undBioingenieurwissenschaftenGruppe MorbidelliETH Hoenggerberg/HCI F1258093 ZurichSwitzerlandXXXIV List of ContributorsProf. R. A. T .M. van BenthemCoating TechnologyDepartment of Chemical Engineeringand ChemistryEindhoven University of TechnologyP.O. Box 5135600 MB EindhovenThe NetherlandsDr. M. van DuinDSM ResearchOude Postbaan 16167 RG GeleenThe NetherlandsList of Contributors XXXV1Polymer Reaction Engineering, an IntegratedApproachTh. Meyer and J. T. F. Keurentjes1.1Polymer MaterialsSynthetic polymers can be denoted as the materials of the 20th century. SinceWorld War II the production volume of polymers has increased by a factor of 50to a current value of more than 120 million tonnes annually (Figure 1.1). The con-sumption per capita has also increased over the years to a worldwide average of ap-proximately 20 kg per annum in the year 2000. In terms of volumetric output, theproduction of polymers exceeds that of iron and steel. The enormous growth ofsynthetic polymers is due tot the fact that they are lightweight materials, act as in-sulators for electricity and heat, cover a wide range of properties from soft packag-ing materials to bers stronger than steel, and allow for relatively easy processing.Handbook of Polymer Reaction Engineering. Edited by T. Meyer, J. KeurentjesCopyright 8 2005 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 3-527-31014-205101520251940 1950 1960 1970 1980 1990 2000Year020406080100120Annual Production 106 to/an World Population , 109 peopleConsumption, kg/hab2010Fig. 1.1. Polymer production and the evolution of the population since 1940 [1].1Moreover, parts with complex shapes can be made at low cost and at high speed byshaping polymers or monomers in the liquid state.The polymer market can be divided into thermoplastics and thermosets. The ma-jor thermoplastics include high-density polyethylene (HDPE), low-density polyeth-ylene (LDPE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene(PS and EPS), poly(vinyl chloride) (PVC), polyamide (PA), poly(methyl methacry-late) (PMMA) and styrene copolymers (ABS, SAN). The most important applica-tions of thermoplastics are summarized in Table 1.1. The total Western Europeandemand for thermoplastics was 37.4 million tonnes in 2002, a growth of about 9%as compared to 2001 [1]. Thermoplastics are used not only in the manufacture ofmany typical plastics applications such as packaging and automotive parts, but alsoin non-plastic applications such as textile bers and coatings. These non-plastic ap-plications account for about 14% of all thermoplastics consumed.The major thermosets include epoxy resins, phenolics, and polyurethanes (PU),for which the major applications are summarized in Table 1.2. It has to be noted,Tab. 1.1. Applications and 2002 Western European markets for the major thermoplastics [1].Thermoplastic Market[103tonnes]ApplicationsLDPE 7935 pallet and agricultural lm, bags, toys, coatings,containers, pipesPP 7803 lm, battery cases, microwave-proof containers, crates,automotive parts, electrical componentsPVC 5792 window frames, pipes, ooring, wallpaper, bottles, clinglm, toys, guttering, cable insulation, credit cards,medical productsHDPE 5269 containers, toys, housewares, industrial wrappings andlms, pipesPET 3234 bottles, textile bers, lm food packagingPS/EPS 3279 electrical appliances, thermal insulation, tape cassettes,cups and plates, toysPA 1399 lm for food packaging (oil, cheese, boil-in-bag), high-temperature engineering applications, textile bersABS/SAN 788 general appliance moldingsPMMA 317 transparent all-weather sheet, electrical insulators,bathroom units, automotive partsTab. 1.2. Applications and 2002 Western European markets for the major thermosets [1].Thermoset Market [103tonnes] ApplicationsPU 3089 coatings, nishes, cushions, mattresses, vehicle seatsPhenolics 912 general appliance moldings, adhesives, appliances,automotive parts, electrical componentsEpoxy resins 420 adhesives, automotive components, E&E components,sports equipment, boats2 1 Polymer Reaction Engineering, an Integrated Approachhowever, that about one-third of the market for thermosets is for relatively small-scale specialty products. The total Western European market for thermosets was10.4 million tonnes in 2002, about 1% below the 2001 value.The major application areas of polymers can be dened as follows (Figure 1.2).Automotive industry Motorists want high-performing cars combined with reliabil-ity, safety, comfort, competitive pricing, fuel eciency, and, increasingly, reassur-ance about the impact on the environment. Lightweight polymeric materials areincreasingly used in this sector (Daimler Benzs Smart is a nice example), also con-tributing to a 10% reduction in passenger fuel consumption across Europe.Building and construction Polymeric materials are used in the building and con-struction sector, for example for insulation, piping, and window frames. In 2002this sector accounted for 17.6% of the total polymer consumption.Electrical and electronic industry Many applications in this eld arise from newlydesigned polymeric materials, for example for polymeric solar cells and holo-graphic lms. It is interesting to note that, while the number of applications inthis eld is increasing, the weight of the polymers used per unit is decreasing.Packaging The packaging sector remains the largest consumer of synthetic poly-mers, approximately 38% of the total market. This is mainly due to the fact thatthese materials are lightweight, exible, and easy to process, and are thereforeincreasingly being substituted for other materials. Although polymer packagingranks rst in terms of units sold, it is only third if judged on weight.Agriculture As agricultural applications account for about 2.5% of the total of syn-thetic polymers consumed in Europe, they play only a marginal role. Irrigation andPackaging38.1%Building and construction17.6%Electrical and electronics7.3%Large industry5.2%Automotive7.0%Agriculture2.5%Domestic22.3%Fig. 1.2. Plastic consumption in 2002 by industry sectors in Western Europe [1].1.1 Polymer Materials 3drainage systems provide eective solutions to crop growing, and polymeric lmsand greenhouses can increase horticultural production substantially. The use of so-called super absorbers for increased irrigation eciency in arid areas can be con-sidered an important emerging market.1.2A Short History of Polymer Reaction EngineeringIn Table 1.3 a comprehensive overview of the major developments in the polymerindustry is given. In the 19th century, polymers produced by Nature, such as cellu-lose, Hevea brasiliensis latex (natural rubber), and starch, were processed to manu-facture useful products. This practice was often based on experimental discoveries.As an example, in 1839 Goodyear discovered by mistake the sulfur vulcanization ofnatural rubber, making it possible for Ford to develop the automotive market. Inthose times no polymers were produced synthetically.Early in the 20th century (1920), the rst empirical description of macromole-cules was developed by Staudinger [2]. At the same time, new methods were devel-oped to determine the specic characteristics of these materials. In the 1930s manyresearch groups (for examples see refs. 37) developed models for the chain lengthdistribution in batch reactors resulting from dierent polymer chemistries, a meth-odology that was further developed in the 1940s leading to more complex and com-prehensive models, some of which are still being used today.Tab. 1.3. The history of polymers in brief.19th century natural polymer and derivatives (vulcanized rubber, celluloid)1920 concept of macromolecules postulated by Staudinger19301940 rst systematic synthesis of polymerssynthesis of polyamides (nylon) by Carothers at DuPontdiscovery of polyethylene at ICI (Fawcett and Gibson)19401950 synthetic rubbers and synthetic bers19501960 stereospecic polymerizations by Ziegler and Natta, the birth ofpolypropylenediscovery of polymer single crystals (Keller, Fischer, Till)development of polycarbonate19601970 discovery of PPO at GE by Hay and commercialization of PPO/PSblends (Noryl2)19701980 liquid-crystalline polymers19801990 superstrong bers (Aramid2, polyethylene)functional polymers (conductive, light-emitting)19902000 metallocene-based catalysts; novel polyolens hybrid systems(polymer/ceramic, polymer/metals)2000 Nature-inspired catalystssynthesis of polymers by bacteria and plants4 1 Polymer Reaction Engineering, an Integrated ApproachAround 1940, partly inspired by World War II, a more systematic search for newsynthetic polymer materials as a replacement for scarce natural materials led to thedevelopment of nylon (DuPont) and polyethylene (ICI) [8, 9]. This was followed bythe development of synthetic rubbers and synthetic bers. In the same period,Denbigh [10] was one of the rst to introduce chemical reaction engineering con-cepts into polymer science by considering polymerization reactions at both thechemical and at the process levels. Processes were classied as homocontinuousand heterocontinuous, depending on the mixing level. This pioneering approachalso acted as a catalyst for the further development of polymer reaction engineer-ing (PRE).The development of catalysts based on transition metals by Ziegler and Natta[11] allowed the development of stereospecic propylene polymerization processesand ethylene polymerization in the 1950s. Several process schemes were developedat that time, of which some are still in use. The major problem in process develop-ment has been to deal with the heat of polymerization, an issue that was solved, forexample, by using an inert solvent as a heat sink or by ashing of monomer fol-lowed by condensation outside the reactor. In the same period, polycarbonate and(somewhat later) poly(propylene oxide) (PPO) were developed. The main character-istic of the polymers developed so far was that they were bulk materials, to be pro-duced in extremely large quantities.In the 1970s, a paradigm shift occurred when polymers with more specic prop-erties started to be produced. This included various liquid crystalline polymersleading, for example, to the production of superstrong bers such as Aramid2/Kevlar2 [12]. The development of functional polymers for the conduction of lightand electricity and optical switches also started then [13]. In the near future thiswill probably lead to highly eective and exible polymer solar cells [14].In the 1990s, metallocene catalysts were developed for polyolen production thatsurpassed the ZieglerNatta catalysts in terms of selectivity and reactivity [15, 16].Additionally, various hybrid materials were combining properties of both the poly-mer (lightweight, exible) and a solid material, which could be metal (conductive)or ceramic (insulating), leading to materials with specic properties applicable, forexample, as protective coatings [17].Current developments include the mimicking of nature (enzymes) for the syn-thesis of quite complex polymers like natural silk. Also, bacteria and plants are be-ing modied to produce polymers of interest [18]. However, this can be expectedto require polymer reaction engineering developments that are as yet dicult toforesee.1.3The Position of Polymer Reaction EngineeringTraditional chemical reaction engineering has its basis in the application of scien-tic principles (from disciplines such as chemistry, physics, biology, and mathe-matics) and engineering knowledge (transfer of heat, mass, and momentum) to1.3 The Position of Polymer Reaction Engineering 5the solution of problems of practical, industrial, and societal importance. Since the1970s, a changing focus in chemical reaction engineering can be observed, whichis summarized in Figure 1.3.To deal with more stringent requirements in terms of energy consumption re-quires a shift from heat loss minimization toward novel intensied process con-cepts that intrinsically require less energy. Safety should now be considered as anintrinsic plant property rather than a responsive action, and the plant needs to beexible to be able to respond quickly to changes in the market. Last but not least,new concepts will be required to provide a basis for sustainable future develop-ments, that is, the use of renewable resources and processes based on greensolvents. As a result of this changing focus, a shift toward a multidisciplinaryapproach can be observed.For PRE this implies the combination of several disciplines such as polymerchemistry, thermodynamics, characterization, modeling, safety, mechanics, phys-ics, and process technology. PRE problems are often of a multi-scale and multi-functional nature to achieve a multi-objective goal. One particular feature of PREis that the scope ranges from the micro scale on a molecular level up to the macroscale of complete industrial systems. PRE plays a crucial role in the transfer of in-formation across the boundaries of dierent scale regions and to provide a compre-hensive and coherent basis for the description of these processes [19].As depicted in Figure 1.4, there is a direct link between time and size scale, fromwhich it is obvious that the micro and macro scales are not related to the sametime scale [20]. As an example, molecular dynamics calculations are addressing atime scale in the order of femto- to nanoseconds, whereas process system integra-tion evolves on the scale of years. Engineers have traditionally been working at themeso scale, which is represented by the middle portion of Figure 1.4, using phe-1980 1990 2000 2010Integrated heat recoveryCoal, Oil Natural gas Renewable feedstockPlant operation Integrated and inherent safetyCapacity Quality control Flexible productionWater Air RecyclingClean processes Green solventsFrom empiricism to strategy MultidisciplinarityOptimization IntensificationEnergyRaw materialSafetyMarketPollution controlScientific methodologyProcessLess energy demanding processesFig. 1.3. Changing priorities in industrial chemical engineering research.6 1 Polymer Reaction Engineering, an Integrated Approachnomenological and continuum models. Today these limits are pushed in two direc-tions, both toward a more fundamental understanding and at the same time to-ward a more global scale. In the past, the micro-region has traditionally beenthe domain of physicists and chemists, whereas the macro-region has been theeld, rather, of process or plant engineers. Today, it becomes obvious that only us-ing a multidisciplinary, parallel, and synergetic approach can lead to successful de-velopments. Polymer reaction engineering will play an essential role as the coreand the coordinator of this complex process.1.4Toward Integrated Polymer Reaction EngineeringAs will be obvious from the foregoing discussion, PRE is composed of many disci-plines all linked together. These disciplines can be either mature or emergent, butthey have a common gateway (see Figure 1.5). Although there is not necessarily adirect connection between them, there exists a common core in which the dierentdisciplines make their own specic contribution to a general objective.The frontiers in PRE are determined by what we know, understand, and are ableto quantify, and these frontiers are moving with growing knowledge, competences,and experience. Eorts to push these limits will induce innovative developmentsleading to emerging technologies and products, and will also strengthen the multi-disciplinary approach. In general terms, PRE can be dened as the science thatTime scaleSize scaleYearsDaysMinutesMillisecondsNanosecondsPicosecondsFemtoseconds1 10 100 1m 1mm 1m 1kmAtomic level FundamentalQuantum techniquesQuantum chemistryMolecular level Elementary reactionsMolecular modelingChemical equilibriumPhenomenological ModelsMicrostructureContinuum ModelsHeterogeneousEngineering designProcess modelsSystem integrationEnvironmental, GlobalmodelingFig. 1.4. Activities in PRE with their corresponding time and size scales.1.4 Toward Integrated Polymer Reaction Engineering 7brings molecules to an end-use product. We can either consider it like a black box(Figure 1.6) or we can try to dene the interconnected disciplines that composethis black box (Figure 1.7). Provided the required product properties can be met,we expect that sustainability is the common denominator for all the disciplines in-volved in this process.The process of transforming raw materials into valuable end-use products is nota one-way procedure but rather an iterative process in which we try to optimize allthe parameters involved. The selection of the proper chemistry and technologyshould include an evaluation of environmental, safety, and economic parameters.Moreover, questions regarding the possible use of renewable resources and mini-mizing the energy requirement will have to be answered. Dening PRE in thismanner appears to be very close to the procedure of life cycle analysis (LCA) [21].Polymer ReactionEngineering(PRE)Polymer chemistryReaction kineticsProcess integrationoptimizationInherent safetyEnvironmentRecycling, DisposalNovel processesNew productsMaterialsApplicationModeling andsimulationThermodynamicsNovel processesPost-reactionprocessesMeasurement and controlMaterials sciencesNano-, Micro-Bio-Fig. 1.5. The expanding sphere of polymer reaction engineering.Polymer Reaction EngineeringRaw materials End use productFig. 1.6. PRE as a black box process.8 1 Polymer Reaction Engineering, an Integrated ApproachLife cycle analysis is a tool assisting decision making in the engineering process.LCA includes the information on the history of the materials used, and the dif-ferent process and raw material alternatives, as well as the nal product require-ments. LCA is an instrument driven by environmental considerations against abackground of technical and economic specications, and involves the so-called 3-P concept (people, planet, and prot). The LCA-based PRE methodology (Figure1.8) [22] leads to an optimization of all the parameters involved and a reduction ofthe costs. This seems to be contradictory at rst sight, but integrating all the as-pects often leads to cost reductions. In our view, the use of this approach will leadto a sustainable integrated PRE.1.5The Disciplines in Polymer Reaction EngineeringThe dierent disciplines involved in PRE can be represented using the academiaindustry dichotomy (Figure 1.9). The interests of the two types of players are notidentical: the dierences are similar to the dierences in their mission statements.Nevertheless, we can observe that a great overlap is present in the middle zone,Integrated PREPolymer chemistryReaction kineticsProcess integrationoptimizationInherent safetyEnvironmentRecycling, DisposalNovel processesNew productsMaterialsApplicationModeling andsimulationThermodynamicsNovel processesPost-reactionprocessesMeasurement and controlMaterials sciencesNano-, Micro-Bio-Raw materialsEnergiesNeedsLawsEconomySustainabilityRenewableProductsProfitSatisfactionKnowledgeFig. 1.7. The integrated approach for sustainable PRE.1.5 The Disciplines in Polymer Reaction Engineering 9where interests, tools, and knowledge are similar, thus providing a strong basis forpartnership.As stated above, PRE is composed of a large number of disciplines, which aredescribed in more detail in the following chapters of this handbook. These disci-plines are interconnected by a synergetic and multidisciplinary approach, and com-processingsynthesisraw materialproduct userecyclingwastemanagementSpecification- technical- economic- ecologic- safetyBalances- energy- material- emission- waste- sewageEvaluation leads to closedloop assessment of costsFig. 1.8. Life cycle analysis of parts, methods, products, and systems.AcademiaIndustrySafetyProcessmodelingMolecular modelingReactor designMeasurementand controlFundamentalkineticsThermodynamicsQualityassuranceNoveltechnologiesMarketeconomicsPolymer chemistryPolymer physicsEnvironmentAppliedmodelingFig. 1.9. Overlap of industrial and academic disciplines.10 1 Polymer Reaction Engineering, an Integrated Approachmercial products are the nal achievement resulting from this methodology. Thiscould be expressed by an orthogonal representation (Figure 1.10) where polymersciences are linked with engineering sciences. Every type of polymerization willhave its own specic features, models, and engineering aspects involved. From Fig-ure 1.10 it will be obvious that only teamwork, bringing together several elds ofexpertise, can lead to the nal objective.1.5.1Polymerization MechanismsPolymerization reactions can be classied depending on the reaction mechanisminvolved and can be either step-growth or chain-growth. These mechanisms dierbasically with the time scale of the process. In step-growth polymerization (likepolycondensation), the polymer chain growth proceeds slowly from monomer todimer, trimer, and so on, until the nal polymer size is formed at high monomerconversions. Both the chain lifetime and the polymerization time are often in theorder of hours. In chain-growth polymerization (like ionic or free-radical polymer-ization), macromolecules grow to full size in a much shorter time (seconds beingthe order of magnitude) than required for high monomer conversion. High molec-ular weights are already obtained at low monomer conversion, which is in greatcontrast to step-growth polymerizations. Also, unlike step-growth polymerization,chain-growth polymerization requires the presence of an active center.Condensation polymers are the result of a condensation reaction between mono-mers, with or without the formation of a condensation by-product (Chapter 3). Ex-amples of polymers produced by condensation are polyamide[6.6], (Nylon 6,6) theresult of the intermolecular condensation of hexamethylenediamine and adipicacid, and polyamide[6], (Nylon 6) which is the product of intramolecular condensa-tion of a-caprolactam. This type of reaction is generally sensitive to thermodynamicequilibrium and requires the removal of the by-product, which is often volatile.PolycondensationFig. 1.10. Product-driven PRE, based on an orthogonalrelationship between science and engineering.1.5 The Disciplines in Polymer Reaction Engineering 11The polymers produced by condensation reactions can be either linear or non-linear, depending on the number of functional groups per monomer. The polymer-ization process can be performed in bulk (liquid or solid state) or as an interfacialpolymerization.Free-radical polymerization (FRP) can be performed homogeneously (in bulk, so-lution, or suspension; Chapters 4 and 5) or heterogeneously (emulsion, precipita-tion; Chapter 6). The active site is always a radical that can be unstable (classicalFRP) or stabilized as in pseudo-living FRP. Radicals can be formed by the homo-lytic bond rupture of initiators (molecules sensitive to homolytic cleavage, such asperoxides, photosensitive molecules, or bisazo compounds) or by complex mecha-nisms creating radicals from monomer units using thermal or high-energysources, such as X-rays, g-irradiation, or UV. This type of polymerization usuallycomprises several steps: initiation, propagation, various transfer mechanisms,and termination.In ionic polymerizations a cation or anion is the active site (Chapter 7). A heter-olytic process leads to charged parts of molecules that can induce the polymeriza-tion by nucleophilic or electrophilic processes. These reactions generally evolve atlow temperatures (even as low as 120

C) due to the high reactivity of ions. Also,they are very sensitive to impurities present in the monomer or solvent. These re-actions are not always terminated, so lead to living polymerization. This process isoften used to build tailor-made copolymers.Coordination polymerizations require a transition metal catalyst (Chapter 8). Poly-olens are often produced by this kind of reaction where the catalyst (ZieglerNatta, for example) acts as the active site but also as the steric regulator, whichmakes it possible to build polymers with a dened tacticity. Nowadays a great re-search eort is devoted to the synthesis of new transition metal-based catalysts,such as metallocenes, to produce new products.1.5.2Fundamental and Engineering SciencesApart from the various polymerization mechanisms involved, a large number ofother disciplines will have to be involved, according to the matrix depicted inFigure 1.10.Thermodynamics is essential to understand the physicochemical properties ofthe individual reactants, solvents, and products involved (Chapter 2). Also, it pro-vides information on the interaction between the various components present inthe reaction mixture, from which phenomena such as phase behavior and parti-tioning can be derived. This information is usually accessible by using the appro-priate equation of state for a given system studied. A close collaboration betweenchemical physicists, chemists, and chemical engineers is required to take full ad-vantage of this fundamental knowledge.Polymer solutions (solid, bulk, solution, complex media) have to be characterizedby several specic analytical tools (Chapter 20). Techniques such as NMR, ESR,12 1 Polymer Reaction Engineering, an Integrated Approachelectron microscopy, chromatography, electrophoresis, viscometry, calorimetry, andlaser diraction are widely used to determine polymer properties, often in combi-nation. The main characteristics being analyzed are the chain length distribution,degree of branching, composition, tacticity, morphology, particle size, and chemicaland mechanical properties. Polymer mechanics (Chapter 14) usually concerns thenal product rather than the polymerization reaction. Nevertheless, as polymersare usually judged on their end-use properties (Chapter 13), the nal productneeds specic and often customer-based analysis. This is described more speci-cally for two application areas, namely the use of thermosets for coating applica-tions (Chapter 16) and the production of polymeric bers (Chapter 17).Measurement and control are indispensable to achievement of a robust and safeprocess (Chapter 12). Since the early 1990s, a tremendous eort has been observedin the development of new in-line analytical techniques, including spectroscopy(UV, IR, Raman, laser, and so on), ultrasonic sensing, chromatography, and dirac-tion or electrical methods. New control schemes appear where the reaction is per-formed just below the constraint limits, independently of the reaction kinetics. Allthese techniques tend to lead to safer and more robust processes while increasingproductivity and product quality at the same time.Safety cannot be treated as a separate discipline as it is already integrated fromthe early chemistry and process development (Chapter 11). Safety deals with a widevariety of technological aspects with respect to the environment (water, air, soil,and living species). However, economic aspects are usually taken into consider-ation also. Modern process development intrinsically includes safety and environ-mental aspects in all stages of the development.Modeling is probably the tool of excellence for engineers (Chapter 9). It isused to simulate the reaction and the process system in order to shorten the timefor development. It is based on models that can be physical or chemical, semi-empirical or empirical, descriptive or more fundamental. To describe the develop-ment of the molecular weight distribution upon reaction, moment methods orequations based on population balance are often used.Scaleup is a widely used term to dene the methodology that allows scaling upof a process from small to larger scale (Chapter 10). Often the scaleup process be-gins with a scaledown approach in order to have reliable and representative equip-ment already at the laboratory scale. Scaleup is always dependent on the systemstudied and requires a proper understanding of the performance of process equip-ment involved at dierent scales. In polymer reaction engineering, heat transferand mixing can be considered as two major issues in this perspective. Moderncomputing techniques such as computational uid dynamics and process simula-tion become more and more important in the optimization of process parametersand the equipment hardware.Volatile organic compound (VOC) content in the nal product is related to prod-uct properties and legislation (FDA approval in the USA, for example). All the pro-cesses aiming to lower the residual VOC content in the product are denoted as re-movable (Chapter 18). These processes can dier from each other, depending on1.5 The Disciplines in Polymer Reaction Engineering 13the techniques involved. Devolatilization, post-process reaction, and extraction aresome of the methodologies employed for this purpose.Stability and degradation of polymers (Chapter 15) become relevant especiallyduring post processing or moulding processes. Temperature, oxidation and me-chanic stresses are the main contributors to product degradation.Currently, there is a strong emphasis on the synthesis of novel functional poly-mers shaped on a nano scale (Chapter 19) and the development of sustainableproduction processes (Chapter 21). The latter includes process intensication as amethodology, the use of green solvents, and the use of renewable resources.Many of the new processes under development are focusing on one or more ofthese topics, for which the use of supercritical uids is currently being imple-mented on an industrial scale.1.6The Future: Product-inspired Polymer Reaction EngineeringInnovation times in industry have shown a steady decrease since the 1970s. Classicthinking is that process development becomes increasingly important as industrymatures [23]. This is due to the fact that in an early phase of the lifetime of an in-dustry, when product concepts are still being created, the rate of product innova-tion exceeds the rate of process innovation. This period continues until a dominantdesign has emerged and opportunities for radical product innovation decrease. Inthis phase, the shift is toward process innovations to reduce cost price.The half-time of product innovation (time-to-market) in the early 1970s wasabout ten years. Currently, two years is often considered long. This acceleration ofinnovation time is the result of competitive pressure in the market. As a rule ofthumb, the rst company to enter the market with a new product can get up to60% of market share, so there is a high reward for being rst.As has been discussed above, chemical engineering has been the basis for poly-mer reaction engineering in the past. In recent discussions, however, it has beenemphasized that a need exists to refocus chemical engineering toward product-driven process engineering [24, 25]. The thinking about a process should then startwith the customer or consumer: which of the two depends on the structure of thesupply chain. The wishes of the consumer and consumer-perceived product prop-erties have to be translated into physical and chemical product properties. In thisway, the main physical attributes of a product are determined, including an ideaabout the microstructure. Next, a functional analysis is performed to determinethe lowest number of transformations needed to create the product; this is fol-lowed by a morphological analysis [26]. Finally, a conceptual process design exer-cise is performed to generate possible process routes to achieve the desired productproperties. This sequence of events is the core of product-inspired polymer reac-tion engineering. A key characteristic of this approach is the fact that it avoids theclassical unit operation trap, because it does not x the mindset to consider onlytraditional reactor design and separation process steps to build a process.14 1 Polymer Reaction Engineering, an Integrated Approach1.7Concluding RemarksIn the foregoing we have presented a general framework for sustainable polymerreaction engineering. Its most important characteristic lies in the concerted multi-disciplinary approach, rather than focusing on individual competencies. Given thevolume of polymer production, it will be of major importance that environmentaland safety issues become an integral part of the development process. In combina-tion with tools such as life cycle analysis and product-inspired PRE, this will allowthe development of sustainable new polymer processes.References1 Association of Plastics Manufacturersin Europe, Annual report, 2002.2 H. Staudinger, Chem. Ber., 1920, 53,1073.3 W. Kuhn, Berichte de Deutschen Chem.Gesellsch., 1930, 63, 1503.4 W. H. Chalmers, J. Am. Chem. Soc.,1934, 56, 912.5 H. Dostal, H. Mark, Trans. FaradaySoc., 1936, 32, 54.6 G. V. Schulz, Z. Physik. Chem., 1935,B30, 379.7 P. J. Flory, J. Am. Chem. Soc., 1936,58, 1877.8 W. H. Carothers, US Patent 2 130948, 1937.9 E. W. Fawcett, R. O. Gibson, J.Chem. Soc., 1934, 386.10 K. G. Denbigh, Trans. Faraday Soc.,1947, 43, 648.11 K. Ziegler, E. Holzkamp, H. Breil,H. Martin, Angew. Chem., 1955, 67,541.12 P. W. Morgan, S. L. Kwolek,Macromolecules, 1975, 8, 104.13 H. Sasabe, T. Wada, Polymers forelectronic applications, in: Compre-hensive Polymer Science, vol. 7, S. L.Aggarwal (Ed.), Pergamon Press,Oxford, 1989.14 J. K. J. van Duren, J. Loos, F.Morrissey, C. M. Leewis, K. P. H.Kivits, L. J. IJzendoorn, M. T.Rispens, J. C. Hummelen, R. A. J.Janssen, Adv. Funct. Mater., 2002, 12,665.15 W. Kaminsky, H. Sinn (Eds.) Transi-tion metals and organometallics ascatalysts for olen polymerisation,Springer Verlag, Berlin, 1987.16 J. M. Benedikt, B. L. Goodall,Metallocene-catalyzed polymers, B.F.Goodrich, Brecksville, 1998.17 J. Sinke, Appl. Comp. Mater., 2003, 10,293.18 E. R. Howells, Chem. Ind., 1982, 508.19 A. Penlidis, Can. J. Chem. Eng., 1994,72, 385.20 A. Sapre, J. R. Katzer, Ind. Eng.Chem. Res., 1995, 34, 2202.21 A. Azapagic, Chem. Eng. J., 1999, 73,1.22 P. Eyerer, J. Polym. Eng., 1996, 15,197.23 W. J. Abernathy, J. M. Utterback,Technol. Rev., 1978, 80, 40.24 E. L. Cussler, G. D. Moggeridge,Chemical product design, CambridgeUniversity Press, Cambridge, 2001.25 E. L. Cussler, J. Wei, AIChE J., 2003,49, 1072.26 C. J. King, AIChE Monograph Ser.,1974, 70, 1.References 152Polymer Thermodynamics1Theodoor W. de Loos2.1IntroductionThe phase behavior of polymer solutions plays an important role in polymer pro-duction and processing. Many polymers are produced by solution polymerization.Solvent choice, solvent recovery and the removal of traces of solvent from the poly-mer product are important factors in these processes. An example is the produc-tion of linear low-density polyethylene (LLDPE), which is a copolymer of ethyleneand a 1-alkene. Hydrocarbons are used as solvents in this process. The reactor con-ditions are limited at high temperature by the onset of a liquidliquid phase split,characterized by a lower critical solution temperature, and at low temperature bycrystallization of LLDPE. The pressure must be high enough to keep the ethylenein solution. Another well-known example is the production of low-density polyethy-lene (LDPE). In this process ethylene is compressed together with an initiator andthe LDPE is formed by radical polymerization. The reactor pressure chosen mustbe high enough to dissolve the polymer in its monomer. In practice reactor pres-sures are higher than 200 MPa. Since the conversion of ethylene to LDPE is incom-plete, LDPE has to be separated from unreacted ethylene, which is recycled to thereactor. To save energy this is done by pressure reduction in two steps, which in-volve a high-pressure vaporliquid ash.From a thermodynamic point of view polymer solutions are complicated solu-tions. A polymer is not a single component but a multicomponent mixture charac-terized by a molecular weight distribution or by average molecular weights, such asthe number-average molecular weight Mn or the weight-average molecular weightMw. In the case of a copolymer dierent types of copolymers are possible, for ex-ample random copolymers and block copolymers, and the comonomer contentmay vary. Because of their asymmetric nature the entropy of mixing of polymersolutions is much lower than in the case of a mixture of two low molecular weightcompounds; also, the pure solvent and the polymer have rather dierent freeHandbook of Polymer Reaction Engineering. Edited by T. Meyer, J. KeurentjesCopyright 8 2005 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 3-527-31014-21) The symbols used in this chapter are listed atthe end of the text, under Notation.17volumes. Because of this, polymersolvent systems often show a liquidliquidphase split.In this chapter it is not possible to give an in-depth treatment of the thermody-namics of polymer solutions. For further reading, see Refs. 16.2.2Thermodynamics and Phase Behavior of Polymer Solutions2.2.1Thermodynamic Principles of Phase EquilibriaThe equilibrium conditions for phase equilibria can be derived in the simplest wayusing the Gibbs energy G. According to the second law of thermodynamics, thetotal Gibbs energy of a