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16-PE-12 16-PE-18 16-PE-20 16-PE-22 16-PE-07 16-0-PE-05 16-0-PE-12 16-0-PE-18


In the name of Allah, the Most Gracious and the Most Merciful Alhamdulillah, all praises to Allah for the strength and blessing in completing this thesis. Special appreciation goes to Professor Dr. Naim Masood Hasan , Associate Professor Zaheer Ahmed Chaugtai , Associate Professor Tariq Jamal . Associate Professor Arshad Faruqui for his supervision and constant support. We also wish to acknowledge Laboratory & Technical staff for helping us. Sincere thanks to all our seniors for their support during the study. Last but not least, deepest gratitude goes to our beloved parents for their endless love, prayers and encouragement. To those who indirectly contributed in this research, your kindness means a lot to us. Thank you very much.


TABLE OF CONTENTACKNOWLEDGEMENT..i INTRODUCTION...................................................................................................1 CHAPTER 1. Literature Survey.......2Poly(ethylene terephthalate)..2 History of PET.2 Chemistry of PET..3 Formation of PET.3 Morphology of PET.5 Properties of PET....6 Process ability of PET...6 Application of PET..6

CHAPTER 2. Recycling of PET Plastics...........................................9Introduction...9 PET Recycling..11 History of PET Recycling..11 Effect of Contaminants of PET....11

CHAPTER 3. Physical Recycling Techniques..13Flotation or Hydrocyclone Process..13 Water Bath / Hydrocyclone Process...14

Solvent /Floatation Process..14 Physical Recycling of PET bottle to Form Fibre...15 PET bottles recycling in Pakistan.....19

CHAPTER 4. Chemical Recycling to form Unsaturated Polyester Resin ..22Glycolysis...22 Hydrolysis..24 Methanolysis...25 Chemical Recycling Of Pet on Laboratory Scale..25 Formulation of Recycled Unsaturated Polyester ..26

CHAPTER 5. Applications of Recycled PET..27Unsaturated Polyester Products29 a. b. c. d. GRP Pipes .29 GRP SHEETS.29 GRP Houses.30 Cultured Marble..30

CHAPTER 6. Testing...33Fibre Testing...33 Description of Test for Fibre.33 a. b. c. d. e. f. Denier Testing...33 Cut Length...34 Friction Measurement.34 Draw Ratio...34 Thermal Shrinkage....35 Tensile Strength And Elongation at Break for Fibre........37

Comparison Test Report of Virgin Unsaturated Polyester Resin with Recycled Unsaturated Polyester Resin (8THSemester) .....38 Description of Test for Unsaturated Polyester Resin..39 a. b. c. d. e. f. Density...39 Acid Value....39 Viscosity....39 Gel Time...39 Exothermic Temperature..39 Peak Time..................................................39

CHAPTER 7. Market Survey.....40Local Market Survey..42 International & Local Manufacturer, Supplier & World Scenario..46

CHAPTER 8. Work Plan...48References......49

STUDY OF PET WASTE RECYCLING 2012INTRODUCTIONPoly (ethylene terephthalate), PET is an important engineering thermoplastic which is widely used all around the world. The basic sources of raw materials for PET resin production are crude oil and natural gas. PET is a condensation polymer derived from terephthalic acid (TPA) or dimethyl terephthalate (DMT) and ethylene glycol (EG). The great acceptance of PET as a packaging material is due to its toughness, clarity, capability of being oriented and reasonable cost. Compared to glass, PET containers are lightweight and shatter-resistance. They provide an acceptable barrier and they are considered as the most recyclable plastics in world. Each year millions of tons of PET remain as scrap after being used in several areas. Because of the governmental and environmental regulations, PET is being recycled [1]. In this study, bottle grade and fibre grade Polyester was recycled by two different methods, such as physical recycling and chemical recycling. In physical recycling the PET bottle were crushed washed and extruded to get fibre but In Chemical recycling PET bottle flakes were used, there are different methods in chemical recycling such as, Glycolysis, Hydrolysis, Methanoylsis etc. However, in industry glycolysis method is used for chemical recycling. The main objective of this study is to obtain fibre and unsaturated polyester resin from recycling of PET. In addition to this main objective is to reduce the manufacturing cost of fibre and to manufacture unsaturated polyester resin from bottle grade PET to reduce the manufacturing cost of UP resin and improve the physical and chemical properties of UP resin[2].


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Poly(ethylene terephthalate)Poly (ethylene terephthalate), PET, is one of the most commercially used thermoplastic. PET is a linear condensation polymer that has been used in applications that have seen rapid growth especially as packaging material for carbonated beverages since it was introduced as a container resin. Prior to this surge in use, PET was used as food packaging film, including boil-in-bags for frozen vegetables, and most commonly for the production of fiber for clothing and other applications. The structure of PET is as follows [3].

Figure. Chemical structure of PET


HISTORY OF PETPET has been well known under the name of polyester for more than 60 years. The following milestones mark the development from polyester fibres in the early 1940ies to modern PET bottles. Calico Printers Association [4], a small English company, developed the first laboratory samples of poly (ethylene terephthalate) in fiber form in 1941. Polyester research began in the United States after World War II. Nathaniel C. Wyeth is a inventor of PET bottle. In the 1950s, this research was based on textiles such as DuPont's Dacron and ICI's Terylene. In 1962, the first polyester tire cord was manufactured by Goodyear [4]. In 1977, PET was produced commercially for packaging applications such as film, sheet, coatings, and bottles - although oriented PET film was available in the 1950s. Since then due to the new improvements in mechanical and barrier properties, the consumption of the resin has grown rapidly, primarily for carbonated beverage bottles. 1941: production of first polyester Fibres. 1950s: production of textile fibres (brand names: Trevira, Dralon)


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STUDY OF PET WASTE RECYCLING 2012 1950-60s: extended use in textile industry 1970s: first production of packaging containers End of 1980s: first refillable beverage containers


CHEMISTRY OF PETPET is made industrially by two methods, the first step in each of which involves conversion of the TPA and DMT feed stock with ethylene glycol (EG) into bis (hydroxyethyl) terephthalate (BHET). In the early stages, polymer technology was not developed to produce TPA with sufficient purity. In the early 1960s, pure TPA was produced directly from p-xylene with bromide-controlled oxidation. DMT was made by esterification of terephthalic acid. However, a different process involving two oxidation and esterification stages is now used to produce most DMT. The intermediate product, ethylene oxide is produced by oxidation of ethylene. Then ethylene glycol is obtained by reaction of ethylene oxide with water.


FORMATION OF PETPET is a step-growth (condensation) polymer derived from terephthalic acid (TPA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) according to the following chemical reactions

Figure 2.2 PET formation via acid route

Figure 2.3 PET formations via ester interchange


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STUDY OF PET WASTE RECYCLING 2012In condensation polymerization, if the system is heated with antimony catalyst, a reversible reaction takes place between two polyfunctional molecules to produce one larger polyfunctional molecule, with the possible elimination of a small molecule such as water or methanol. The polycondensation rate is heavily dependent on the type and concentration of the catalyst. The reaction continues until almost all of one of the reagents is used up; an equilibrium is established which can be shifted at high temperatures by controlling the amounts of the reactants and products. Copolyesters, which are produced commercially to reduce the crystallinity of PET, are made by replacing the TPA or EG portion with another dibasic acid or glycol or both. The step growth polymerization occurs in two steps: First, a low molecular weight precursor is formed (BHET), which is then transesterified to form a high molecular weight reactor grade resin. To achieve very high molecular weights (I.V.: 0.72-0.84) and thus avoid thermal degradation in the melt, condensation is also performed in solid phase in a vacuum or under nitrogen. The molecular weights of the PET are adjusted to the intended application area[5], which were given inTable 2.1 Application areas and molecular weights of PET

PET Application Fibers Fibers, low pilling Filaments, textile Filaments, technical Bottles Films

0.57 0.65 0.39 0.51 0.65 0.68 0.65 1.00 0.70 1.00 0.59 0.69

IVDCA (dl/g)

MW Range 38500 - 46000 23000 32000 46000 49000 46000 84000 51000 84000 41000 51000

Solid State Polymerization: Dry monomers can be submitted to solid state polymerization as well as solid prepolymers (i.e., low-molecular-weight polymers derived from conventional polymerization techniques). The former process is usually referred as direct SSP; meanwhile, in