Chemistry and Technologyof Surfactants

Edited by

Richard J. FarnConsultant and former Directorof the British Associationfor Chemical Specialities

Chemistry and Technologyof Surfactants

Chemistry and Technologyof Surfactants

Edited by

Richard J. FarnConsultant and former Directorof the British Associationfor Chemical Specialities

C© 2006 by Blackwell Publishing Ltd

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First published 2006 by Blackwell Publishing Ltd

ISBN-13: 978-14051-2696-0ISBN-10: 1-4051-2696-5

Library of Congress Cataloging-in-Publication Data

Chemistry and technology of surfactants / edited by Richard J. Farn.p. cm.

Includes bibliographical references and index.ISBN-13: 978-1-4051-2696-0 (acid-free paper)ISBN-10: 1-4051-2696-5 (acid-free paper) 1. Surface chemistry. 2. Surface active agents.

I. Farn, Richard J.QD506.C446 2006541′.33–dc22 2005017738

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Contents

Contributors xi

Preface xiii

Glossary xv

1 What Are Surfactants? 11.1 History and applications of surfactants David R. Karsa 1

1.1.1 Introduction 11.1.2 Properties and other criteria influencing surfactant choice 31.1.3 Surfactant applications 51.1.4 Conclusion 7

Appendix: Application guide 81.2 Surfactant market overview: importance in

different industries Joel Houston 141.2.1 Introduction 141.2.2 Consumer 141.2.3 Industrial 21

2 The Basic Theory Hatice Gecol 242.1 Molecular structure of surfactants 242.2 Surface activity 26

2.2.1 Surface tension 262.2.2 Interfacial tension 282.2.3 Surface and interfacial tension reduction 282.2.4 Test methods for surface and interfacial tension measurements 31

2.3 Self-assembled surfactant aggregates 322.3.1 Micelles and critical micelle concentration 332.3.2 Aggregate structures and shapes 35

2.4 Adsorption of surfactants at surfaces 382.4.1 Adsorption at liquid–gas and liquid–liquid interfaces 382.4.2 Adsorption at liquid–solid interface 39

vi Contents

Acknowledgement 43References 43

3 Applied Theory of Surfactants Peter Schmiedel and Wolfgang von Rybinski 463.1 Introduction 463.2 Detergency 47

3.2.1 Fundamental processes 473.2.2 Basic formulae of detergents and cleansers 483.2.3 Adsorption at the solid–liquid interface 483.2.4 Surface tension and wetting 543.2.5 Interplay of surfactants with other detergent ingredients 60

3.3 Phase behaviour of surfactants 623.3.1 Introduction 623.3.2 Surfactant phases 623.3.3 Impact of the phase behaviour on detergency 66

3.4 Emulsions 693.4.1 Introduction 693.4.2 Emulsion types 703.4.3 Breakdown of emulsions 74

3.5 Foaming and defoaming 763.5.1 Introduction 763.5.2 Stabilising effects in foams 773.5.3 Correlation of foamability with interfacial parameters 783.5.4 Foam control 81

3.6 Rheology of surfactant solutions 823.6.1 Introduction 823.6.2 Rheological terms 833.6.3 Rheological behaviour of monomeric solutions and

non-interacting micelles 833.6.4 Entanglement networks of rod-like micelles 843.6.5 The rheological behaviour of bilayer phases 86

References 88

4 Anionic Surfactants John Hibbs 914.1 Sulphonates 92

4.1.1 Alkylbenzene sulphonates 934.1.2 α-Olefin sulphonates 1024.1.3 Paraffin sulphonates 1044.1.4 Sulphonated methyl esters 1064.1.5 Sulphonated fatty acids 1084.1.6 Sulphosuccinates 110

4.2 Sulphates 1134.2.1 Alkyl sulphates 1134.2.2 Alkyl ether sulphates 118

4.3 Phosphate esters 122

Contents vii

4.4 Carboxylates 1244.4.1 Soap 1244.4.2 Ether carboxylates 1264.4.3 Acyl sarcosinates 1274.4.4 Alkyl phthalamates 1284.4.5 Isethionates 1294.4.6 Taurates 130

References 132

5 Non-ionic Surfactants Paul Hepworth 1335.1 Introduction 1335.2 General alkoxylation reactions 1335.3 Alkyl phenol ethoxylates 1355.4 Fatty alcohol ethoxylates 1365.5 Polyoxethylene esters of fatty acids 1395.6 Methyl ester ethoxylates 1405.7 Polyalkylene oxide block co-polymers 1415.8 Amine ethoxylates 1425.9 Fatty alkanolamides 1435.10 Amine oxides 1445.11 Esters of polyhydric alcohols and fatty acids 1455.12 Glycol esters 1465.13 Glycerol esters 1465.14 Polyglycerol esters 1465.15 Anhydrohexitol esters 1475.16 Polyoxyalkylene polyol esters 1485.17 Alkyl poly glucosides 1495.18 Gemini surfactants 150References 151

6 Other Types of Surfactants 1536.1 Cationics J. Fred Gadberry 153

6.1.1 Introduction and background 1536.1.2 Manufacturing processes 1536.1.3 Applications of cationic surfactants 1566.1.4 Industrial applications of cationic surfactants 165

References 1666.2 Amphoteric surfactants Richard Otterson 170

6.2.1 Introduction 1706.2.2 Aminopropionates and Iminodipropionates 1706.2.3 Imidazoline-based amphoteric surfactants 1726.2.4 Betaine surfactants 1806.2.5 Other amphoteric surfactants 1846.2.6 Summary 185

References 185

viii Contents

6.3 Silicone surfactants Randal M. Hill 1866.3.1 Introduction 1866.3.2 Structures 1876.3.3 Synthesis 1896.3.4 Hydrolytic stability 1916.3.5 Surface activity 1916.3.6 Wetting 1926.3.7 Phase behavior 1946.3.8 Ternary systems 1956.3.9 Applications 196

References 1996.4 Polymerizable surfactants Guido Bognolo 204

6.4.1 Introduction 2046.4.2 Reactive surfactants 2046.4.3 Emulsion polymerization 221

Acknowledgements 224References 2246.5 Fluorinated surfactants Richard R. Thomas 227

6.5.1 Introduction 2276.5.2 Uses 2276.5.3 Applied theory 2286.5.4 Environmental considerations 2316.5.5 Latest developments 231

References 235

7 Relevant European Legislation 2367.1 Biodegradability Paul J Slater 236

7.1.1 Biodegradation of surfactants 2367.1.2 Sewage treatment plants 2377.1.3 Measurement of biodegradability 2387.1.4 Legislation 2397.1.5 Detergents Regulation 243

References 2467.2 Classification and labelling of surfactants Richard J Farn 248Acknowledgement 248References 2497.3 The European Commission’s New Chemicals Strategy (REACH)

Philip E. Clark 2507.3.1 Introduction 2507.3.2 History of chemicals legislation 2507.3.3 The principles behind REACH 2517.3.4 REACH 2517.3.5 The impact on the surfactant industry 257

Contents ix

7.3.6 Testing cost 2587.3.7 Conclusion 258

References 2597.4 The Biocidal Products Directive Mike Bernstein 260

7.4.1 Introduction 2607.4.2 The Directive 2607.4.3 Some definitions 2607.4.4 Requirements and operation 2617.4.5 Costs 2627.4.6 Transitional measures 2637.4.7 Data protection and ‘free-riding’ 2657.4.8 Impact 2657.4.9 Final comment 267

References 268

8 Relevant Legislation – Australia, Japan and USA 2698.1 Relevant legislation – Australia John Issa 269

8.1.1 Introduction 2698.1.2 National Industrial Chemicals Notification and

Assessment Scheme 2698.1.3 Food Standards Australia New Zealand 2768.1.4 National Drugs and Poisons Scheduling Committee 2778.1.5 Therapeutic Goods Administration 2788.1.6 Hazardous substances 2788.1.7 Dangerous goods 2808.1.8 Eco labelling in Australia 282

References 2838.2 Japanese legislation relating to the manufacture and use of surfactants

Yasuyuki Hattori 2848.2.1 Chemical substances control law and industrial safety and health

law 2848.2.2 Pollutant release and transfer register system 288

References 2938.3 Relevant US legislation Arno Driedger 294

8.3.1 General 2948.3.2 TSCA 2948.3.3 FDCA 2958.3.4 FIFRA 2978.3.5 Other pertinent regulations 297

References 298

9 Surfactant Manufacturers Richard J Farn 300

Index 311

Contributors

M. Bernstein ChemLaw UK, MWB Business Exchange, 494 Midsummer Boulevard,Central Milton Keynes, MK9 2EA, UK

G. Bognolo WSA Associates, Schuttershof 2 B-3070, Everberg, Belgium

P. E. Clark Lakeland Laboratories Limited, Peel Lane, Astley Green, Tyldesley,Manchester M29 7FE, UK

A. Driedger Arno Driedger Consulting, 3131 Wilson Street, Conklin, MI 49403, USA

R. J. Farn Phoenix House, Arkholme, Carnforth, Lancashire LA6 1AX, UK

J. F. Gadberry Surfactants America Research, Akzo Nobel Chemicals –Surface Chemistry, Dobbs Ferry, New York, USA

H. Gecol Chemical Engineering/MS170, University of Nevada Reno, Reno, NV 89557,USA

Y. Hattori Technical Regulatory Affairs Centre, Product Quality Management Division,Kao Corporation, 2-3-1 Bunka Sumida-ku, Tokyo 131-8051, Japan

P. Hepworth Merrington Cottage, Oulston, York YO61 3RA, UK

J. Hibbs Mclntyre Limited, Holywell Green, Halifax West Yourkshire, HX4 9DL. UK

J. Houston R M Hill Dow Corning Corporation, ATVB Materials Science, 2200 WSalzburg Road, Midland, MI 18686, USA

J. Issa Cintox Pty Ltd, 121 Carlton Crescent, PO Box 168, Summer Hill, NSW 2130,Australia

D. R. Karsa TensioMetrics Ltd., 10 Barnfield Road East, Stockport SK3 8TT, UK

R. Otterson McIntyre Group, 24601 Governors Highway, University Park, IL 60466, USA

P. Schmiedel Dept VTR- Physical Chemistry, Henkel KGaA, Henkelstrasse 67, 40191Dusseldorf, Germany

P. J. Slater Shield Consulting, 17 Oregon Walk, Wokingham, Berkshire RG40 4PG, UK

xii Contributors

R. R. Thomas OMNOVA Solutions Inc., 2990 Gilchrist Road, Akron, OH 44305-4418,USA

W. von Dept VTR – Physical Chemistry, Henkel KGaA, Henkelstrasse 67, 40191Rybinski Dusseldorf, Germany

Preface

This book is designed to give practical help to those involved with the use of surface activeagents or surfactants as they are more generally known. It is intended particularly for newgraduate and post graduate chemists and chemical engineers at the beginning of theirindustrial careers and for those who, in later life, become involved with surfactants for thefirst time. It aims to give practical help to the formulator by providing a straightforward andapplication led survey of the manufacture, chemistry and uses of surfactants.

Surfactants are not new: the oldest surfactant is soap which dates back well over 2000 yearsalthough the modern surfactant industry has developed essentially since the Second WorldWar, utilising the expansion of the petrochemical industry as one of its main sources of rawmaterials. Chapter 1 covers the development of the industry and elaborates on the impor-tance of surfactants in modern day living and the very many areas where they find application.

Surfactants are generally classified by ionic types which relate to their chemical structureand are described as anionic, non-ionic, cationic and amphoteric. Following descriptions ofthe theory behind surfactants, each category is considered with a brief summary of methodsof manufacture but with the main emphasis on properties and applications.

In choosing surfactants for a given application, it is no longer sufficient to discover a singleproduct or, more generally, a blend which will do the job: one must now take into accountrelevant legislation which can restrict the use of some materials. In particular, the EuropeanDetergents Regulation is now in force requiring, inter alia, ultimate biodegradation or min-eralisation of surfactants for certain applications. Other regulations such as the DangerousSubstances and Preparations Directives, the Biocidal Products Directive and the proposedREACH (Registration, Evaluation and Authorisation of Chemicals) legislation are relevantand restrictive throughout the European Community. Other, sometimes similar, legislationis in force throughout different parts of the world and all this is covered towards the end ofthe book.

Finally, commercial availability at the right price is of major importance and a list of themain manufacturers of the different types of surfactants is included.