Polyacrylamide Emulsions Handbook - SNF Emulsions Handbook 1-2 General description of the polyacrylamide emulsions Polyacrylamide emulsions are dispersions or suspensions of

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  • PolyacrylamideEmulsionsHandbook

  • TABLE OF CONTENTS1- INTRODUCTION

    General description of the polyacrylamide emulsions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

    Differences between polyacrylamide emulsions and powders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

    Emulsions are complex liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

    2- STORAGE AND HANDLING OF EMULSIONSBasic principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

    Storage and handling of emulsions : list of situations and operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2Lumps, skins, gels, etc. in the emulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2Settling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3Color of the emulsions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4Pumping an emulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4Filtering an emulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5Spills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6Emulsions exposed to non recommended temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7Compatibility of emulsions with materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8Blends of emulsions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

    Dehydrated emulsions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

    3- POLYMER SOLUTION IN WATER PREPARED FROM AN EMULSIONMaking the polymer solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

    Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2Details on the main parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

    Water quality - Concentration of solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2Shear during inversion - Make-up systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

    Stability of the polymer solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3Generalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3Hydrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3How to assess potential hydrolysis and react to limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4Free radical chain degradation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5

    Bench trials with emulsions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6General recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6Preparations of solutions in laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6Typical application tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

    4- HEALTH, SAFETY, ENVIRONMENTAL INFORMATIONHealth, safety, environmental information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2

    Polyacrylamide Emulsions Handbook

  • INTRODUCTION

    Polyacrylamide Emulsions Handbook

    1

  • Polyacrylamide Emulsions Handbook 1-2

    General description of the polyacrylamideemulsions

    Polyacrylamide emulsions are dispersions or suspensions ofa hydrogel of water soluble polymer in an oil. They are twophases heterogeneous systems and comprise several compo-nents. They are not concentrated polymer solutions. Thehydrated polymer is in the shape of microbeads of 1 micronaverage diameter. These microbeads are dispersed in thehydrocarbon (oil) and stabilized (protected against coagula-tion or agglomeration) by surfactants. The water proportionvaries from 20% to 40% of the final product, depending onthe grade. Water is not considered as free; it is one of the poly-mer gel components.

    Polyacrylamides are high molecular weight water soluble orswellable polymers obtained from water soluble monomers(acrylamide, acrylic acid, adam-methyl chloride, etc.) Theirmain uses are as flocculants in water treatment and mineralprocessing ; drainage and retention aids in the paper industry ;thickening agents etc.

    SNF produces self-inverting emulsions only. This meansthat the polymer can be released in a short time by additionto water, without the need for another chemical.

    Differences between polyacrylamide emul-sions and powders

    Handling of emulsions using pumps is simpler than pow-ders and in many cases, in-line injection can be used, avoidingthe need for an aging tank. Furthermore, dissolution times areshorter and there are almost no solubility problems.

    Unlike powders, emulsions are complex multicomponentproducts which include polymer, surfactants, oil, and water.Packaging and transport costs are greater for emulsions.Powders are very stable during storage whereas emulsionsshow some instabilities (physical settling, skin formation etc.).The presence of oil and surfactants involve more regulationsfor the emulsions than for powders.

    In general, emulsions outperform powders on a dry poly-mer basis and some polymers, with specific chain configura-tions, can only be prepared in emulsion form.

    Emulsions are complex liquids

    Polyacrylamide emulsions can be handled as liquid pro-ducts, but they are not simple liquids. So it is absolutelynecessary for users, prior to any operation, to be informed ofthe specific recommendations that SNF provides hereafterand which concern :

    n how to handle them

    n what care should be taken

    n what are the problems inherent to the nature of emulsions

    n how to overcome these problems

    1

    Oil

    Invertingsurfactant

    Water +polymer

    EMULSIONS OF POLYACRYLAMIDE

    Stabilizersurfactant

    Emulsion of polyacrylamide

  • STORAGE AND HANDLING

    OF EMULSIONS :

    - BASIC PRINCIPLES

    - LIST OF SITUATIONS AND OPERATIONS

    Polyacrylamide Emulsions Handbook

    2

  • Polyacrylamide Emulsions Handbook 2-2

    Storage and handling of emulsions : basicprinciples

    n Emulsions must be stored inside a building at a constanttemperature between 5C and 30C.

    n During the storage and handling, the emulsion must notbe contaminated by water.

    n Emulsions must not be in a situation where the surfacecan dry by ventilation.

    n Emulsions must be sheared as little as possible. Pumping,filtering, stirring etc. must be applied with maximumcare.

    n It is highly recommended to follow SNFs recommenda-tions for equipment and conditions for storage and hand-ling.

    n In the case of any doubt, it is highly recommended toobtain the advice of a technician from SNF.

    Notes to readers :

    - In the following paragraphs: emulsion is the commercialproduct and is a heterogeneous suspension of hydrated polymerin oil . After addition of the emulsion in water, a homogeneoussolution of polymer in water is obtained.

    - Technical details and information on all equipment descri-bed in