Document11

cover

cover

next page >

title: author: publisher: isbn10 | asin: print isbn13: ebook isbn13: language: subject publication date: lcc: ddc: subject:

Cationic Surfactants : Organic Chemistry Surfactant Science Series, 34 Richmond, James M. CRC Press 0824783816 9780824783815 9780585346724 English Surface active agents. 1990 TP994.C384 1990eb 668/.1 Surface active agents.

cover

next page >

file:///D|/New Folder (21)/0824783816/files/cover.html[2010/07/16 11:39:14 ].

cover-0

< previous page

cover-0

next page >

Cationic Surfactants

< previous page

cover-0

next page >

file:///D|/New Folder (21)/0824783816/files/cover-0.html[2010/07/16 11:39:27 ].

cover-1

< previous page

cover-1SURFACTANT SCIENCE SERIES CONSULTING EDITORS MARTIN J. SCHICK Consultant New York, New York FREDERICK M. FOWKES Department of Chemistry Lehigh University Bethlehem, Pennsylvania

next page >

Volume 1: NONIONIC SURFACTANTS, edited by Martin J. Schick VolumeSOLVENT PROPERTIES OF SURFACTANT SOLUTIONS, edited by Kozo 2: Shinoda (out of print) Volume 3: SURFACTANT BIODEGRADATION, by R. D. Swisher (See Volume 18) Volume 4: CATIONIC SURFACTANTS, edited by Eric Jungermann VolumeDETERGENCY: THEORY AND TEST METHODS (in three parts), edited by 5: W. G. Cutler and R. C. Davis VolumeEMULSIONS AND EMULSION TECHNOLOGY (in three parts), edited by 6: Kenneth J. Lissant Volume 7: ANIONIC SURFACTANTS (in two parts), edited by Warner M. Linfield Volume 8: ANIONIC SURFACTANTSCHEMICAL ANALYSIS, edited by John Cross VolumeSTABILIZATION OF COLLOIDAL DISPERSIONS BY POLYMER 9: ADSORPTION, by Tatsuo Sato and Richard Ruch VolumeANIONIC SURFACTANTSBIOCHEMISTRY, TOXICOLOGY, 10: DERMATOLOGY, edited by Christian Gloxhuber (out of print) VolumeANIONIC SURFACTANTSPHYSICAL CHEMISTRY OF SURFACTANT 11: ACTION, edited by E. H. Lucassen-Reynders VolumeAMPHOTERIC SURFACTANTS, edited by B. R. Bluestein and Clifford L. 12: Hilton Volume 13: DEMULSIFICATION: INDUSTRIAL APPLICATIONS, by Kenneth J. Lissant Volume 14: SURFACTANTS IN TEXTILE PROCESSING, by Arved Datyner


cover-1

< previous page

cover-1

next page >


cover-2

< previous page

cover-2

next page >

ELECTRICAL PHENOMENA AT INTERFACES: FUNDAMENTALS, VolumeMEASUREMENTS, AND APPLICATIONS, edited by Ayao Kitahara and Akira Watanabe 15: Volume 16: SURFACTANTS IN COSMETICS, edited by Martin M. Rieger VolumeINTERFACIAL PHENOMENA: EQUILIBRIUM AND DYNAMIC EFFECTS, 17: by Clarence A. Miller and P. Neogi VolumeSURFACTANT BIODEGRADATION, Second Edition, Revised and Expanded, 18: by R. D. Swisher Volume 19: NONIONIC SURFACTANTS: CHEMICAL ANALYSIS, edited by John Cross VolumeDETERGENCY: THEORY AND TECHNOLOGY, edited by W. Gale Cutler 20: and Erik Kissa VolumeINTERFACIAL PHENOMENA IN APOLAR MEDIA, edited by Hans21: Friedrich Eicke and Geoffrey D. Parfitt VolumeSURFACTANT SOLUTIONS: NEW METHODS OF INVESTIGATION, 22: edited by Raoul Zana VolumeNONIONIC SURFACTANTS: PHYSICAL CHEMISTRY, edited by Martin J. 23: Schick Volume 24: MICROEMULSION SYSTEMS, edited by Henri L. Rosano and Marc Clausse VolumeBIOSURFACTANTS AND BIOTECHNOLOGY, edited by Naim Kosaric, W. 25: L. Cairns, and Neil C. C. Gray VolumeSURFACTANTS IN EMERGING TECHNOLOGIES, edited by Milton J. 26: Rosen VolumeREAGENTS IN MINERAL TECHNOLOGY, edited by P. Somasundaran and 27: Brij M. Moudgil VolumeSURFACTANTS IN CHEMICAL/PROCESS ENGINEERING, edited by Darsh 28: T. Wasan, Martin E. Ginn, and Dinesh O. Shah VolumeTHIN LIQUID FILMS: FUNDAMENTALS AND APPLICATIONS, edited by 29: I. B. Ivanov MICROEMULSIONS AND RELATED SYSTEMS: FORMULATION, VolumeSOLVENCY, AND PHYSICAL PROPERTIES, edited by Maurice Bourrel and Robert S. Schecter 30:

< previous page

cover-2

next page >


cover-3

< previous page

cover-3

next page >

VolumeCRYSTALLIZATION AND POLYMORPHISM OF FATS AND FATTY 31: ACIDS, edited by Nissim Garti and Kiyotaka Sato VolumeINTERFACIAL PHENOMENA IN COAL TECHNOLOGY, edited by Gregory 32: D. Botsaris and Yuli M. Glazman VolumeSURFACTANTBASED SEPARATION PROCESSES, edited by John F. 33: Scamehorn and Jeffrey H. Harwell VolumeCATIONIC SURFACTANTS: ORGANIC CHEMISTRY, edited by James M. 34: Richmond VolumeALKYLENE OXIDES AND THEIR POLYMERS, by F. E. Bailey, Jr. and 35: Joseph V. Koleske VolumeINTERFACIAL PHENOMENA IN PETROLEUM RECOVERY, edited by 36: Norman R. Morrow VolumeCATIONIC SURFACTANTS: PHYSICAL CHEMISTRY, edited by Donn N. 37: Rubingh and Paul M. Holland OTHER VOLUMES IN PREPARATION

< previous page

cover-3

next page >


page_i

< previous page

page_i

next page >Page i

Cationic Surfactants Organic Chemistry Edited by James M. Richmond Akzo Chemicals Inc. McCook, Illinois

< previous page

page_i

next page >

file:///D|/New Folder (21)/0824783816/files/page_i.html[2010/07/16 11:40:02 ].

page_ii

< previous page

page_ii

next page >Page ii

Library of Congress Cataloging-in-Publication Data Cationic surfactants: organic chemistry / edited by James M. Richmond. p. cm.(Surfactant science series; v. 34) Includes bibliographical references and index. ISBN 0-8247-8381-6 1. Surface active agents. I. Richmond, James M. II. Series. TP994.C384 1990 668'.1-dc20 90-41605 CIP This book is printed on acid-free paper. COPYRIGHT 1990 by MARCEL DEKKER, INC. All Rights Reserved Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing from the publisher. MARCEL DEKKER, INC. 270 Madison Avenue, New York, New York 10016 Current printing (last digit): 10 9 8 7 6 5 4 3 2 1 PRINTED IN THE UNITED STATES OF AMERICA

< previous page

page_ii

next page >

file:///D|/New Folder (21)/0824783816/files/page_ii.html[2010/07/16 11:40:10 ].

page_iii

< previous page

page_iii

next page >Page iii

Preface Nearly twenty years of research and development activities have passed since the publication of Cationic Surfactants, edited by Eric Jungermann. Numerous workers in the fields of organic chemistry, physical chemistry, analytical chemistry, and biology benefited from that comprehensive coverage of cationic surfactants. Although that work was well accepted by active research workers, advances in the field, the addition of new information to the technology base, and the passage of time made it necessary to publish new volumes in which each discipline is treated separately. This present volume focuses on the organic chemistry of cationic surfactants and includes chapters on a wide array of these unique materials. These chapters are authored by authorities in the field with depth and breadth of experience that no single author could hope to achieve. The authors represent a small subset of many who are active in this field and who have contributed to our knowledge of this area. As editor, I have endeavored to keep the style as consistent as possible, without undue loss of the individuality of each author. Many individuals have contributed to the preparation of this volume, as a multi-authored book requires the cooperation of all who are involved in the endeavor. In that regard, I graciously acknowledge the contributions of the participants, especially the authors, the companies by whom they are employed, and the editorial department of Marcel Dekker, Inc., for their most valuable contributions in the production of this volume. JAMES M. RICHMOND

< previous page

page_iii

next page >

file:///D|/New Folder (21)/0824783816/files/page_iii.html[2010/07/16 11:40:17 ].

page_v

< previous page

page_v

next page >Page v

Contributors Bruce R. Bailey III Akzo Chemicals Inc., The McCook Research Center, McCook, Illinois Daniel R. Berger Akzo Chemicals Inc., The McCook Research Center, McCook, Illinois Gary W. Earl Sherex Chemical Company, Inc., Dublin, Ohio Floyd E. Friedli Sherex Chemical Company, Inc., Dublin, Ohio James F. Gadberry Akzo Chemicals Inc., The McCook Research Center, McCook, Illinois Richard A. Reck Akzo Chemicals Inc., Chicago, Illinois Joe D. Sauer Ethyl Corporation, Baton Rouge, Louisiana Kim R. Smith Ethyl Corporation, Baton Rouge, Louisiana Kenneth E. Visek Akzo Chemicals Inc., The McCook Research Center, McCook, Illinois

< previous page

page_v

next page >

file:///D|/New Folder (21)/0824783816/files/page_v.html[2010/07/16 11:40:26 ].

page_vii

< previous page

page_vii

next page >Page vii

Contents Preface Contributors 1 Fatty Acid Amide Surfactants Kenneth E. Visek 2 Amidoamine Surfactants Floyd E. Friedli 3 Imidazoline Surfactants Gary W. Earl 4 Cationic Surfactants Derived from Petroleum Feedstock Kim R. Smith 5. Cationic Surfactants Derived from Nitriles Richard A. Reck 6 Aromatic and Cyclic Cationic Surfactants Bruce R. Bailey III 7 Miscellaneous Non-Nitrogen-Containing Cationic Surfactants James F. Gadberry iii v

1

51

101

145 163

187

221

< previous page

page_vii

next page >

file:///D|/New Folder (21)/0824783816/files/page_vii.html[2010/07/16 11:40:33 ].

page_viii

< previous page

page_viii

next page >Page viii

8 Polymeric Cationic Surfactants Daniel R. Berger 9 Amine Oxides Joe D. Sauer Index

243

275 297

< previous page

page_viii

next page >

file:///D|/New Folder (21)/0824783816/files/page_viii.html[2010/07/16 11:40:41 ].

page_1

< previous page

page_1

next page >Page 1

1 Fatty Acid Amide Surfactants Kenneth E. Visek Akzo Chemicals Inc., The McCook Research Center, McCook, Illinois 2 I. Introduction 4 II. Synthesis and Purification 4 A. Fatty Acid Amides from Ammonia or Ammonia Derivatives 6 B. Fatty Acid Amides from Triglycerides or Fatty Acid Esters 7 C. Hydrolysis of Nitriles 7 D. Reaction of Fatty Acids or Esters with Polyamines 8 E. Ethoxylated Amides 11 F. Cationic Fatty Acid Amide Surfactants 12 G. Anionic Fatty Acid Amide Surfactants 13 H. Amphoteric Fatty Acid Amide Surfactants 16 I. Purification of Fatty Acid Amides 16 III. Analytical Methods 16 A. Wet Methodsfile:///D|/New Folder (21)/0824783816/files/page_1.html[2010/07/16 11:40:49 ].

page_1

17 B. Gas Chromatography 20 C. High-Performance Liquid Chromatography 21 D. Thin-Layer Chromatography 21 E. Infrared Spectroscopy 23 F. Nuclear Magnetic Resonance Spectrometry 24 IV. Physical Properties 27 V. Commercially Available Fatty Acid Amides 29 VI. Applications 29 A. Lubricants

< previous page

page_1

next page >

file:///D|/New Folder (21)/0824783816/files/page_1.html[2010/07/16 11:40:49 ].

page_2

< previous page

page_2

next page >Page 2 35

B. Surfactants 38 C. Miscellaneous 41 References I Introduction The preparation, properties, commercial availability and uses of fatty acid amides as surfactants are described in this chapter. The initial volume on cationic surfactants, Volume 4: Cationic Surfactants, 1970, edited by Eric Jungermann in the Surfactant Science Series (New York: Marcel Dekker), did not include a chapter on fatty acid amide surfactants [1]. A discussion of some aspects of fatty alkanolamides was presented in Chapter 12, Miscellaneous Nonionic Surfactants, Surfactant Science Series, Volume 1: Nonionic Surfactants, 1967, edited by Martin Schick [2]. Surfactants are classified by the charge carried on the hydrophilic (water-soluble) portion of the molecule. Thus simple fatty acid amides (RCONH2) are nonionic surfactants. Chemical modification of the amide functional group produces more complex fatty acid amides which are either nonionic, cationic, anionic, or amphoteric surfactants of enhanced surface-active properties. In particular, the reaction of carbonyl compounds (fatty acids, esters, and amides) with diethanolamine, to form bis-2-hydroxyethyl fatty acid amide nonionic surfactant derivatives, produces an important class of products which are biodegradable and find considerable utility in the laundry and cosmetics area [3]. Fatty acid amides service many industries [4120]. Table 1 summarizes the application areas that use fatty acid amides extensively. Major end uses for fatty acid amides are as lubricants and surfactants. See Section VI (Applications) for a discussion of these uses. Annual amounts of various fatty acid amides consumed per year in the U.S. surfactant market have been estimated and data are available for several years running [1,121124]. A recent article in Chemical Week indicates the following sector breakdown of the surfactant market in 1986: industrial, 46%; institutional and industrial cleaning, 9%; personal care, 14%; and household, 31% [121]. Skeist Laboratories reported that in 1976 about 4 million pounds of simple fatty acid amides were used in the plastics industry as slip agents [122]. Alkanolamides enjoyed a modest growth of 2.3% per year from 102 to 117 million pounds from 1974 through 1980 [3]. Use of alkanolamides in biodegradable nonionic surfactants (detergents, foam stabilizers, viscosity builders, etc.) was estimated at 66.4 million pounds in 1981 by Colin A. Houston & Associates, Inc. [123]. In

< previous page

page_2

next page >


page_3

< previous page

page_3

next page >Page 3

TABLE 1 Fatty Acid Amide Surfactant Markets Market References Lubricants 46 714 External 1521 Internal Surfactant 2224 2528 Dispersants 2940 Cleaners 4167 Detergents 6877 Shampoos 7880 Collectors Miscellaneous 8188 Fabric softeners 8992 Antistatic agents 62, 9395 Antimicrobial agents 96103 Dye dispersing agents 104114 Corrosion inhibitors 115119 Antifoaming agents 120 Pulping aids 1985, 60 million pounds of alkanolamides was used in the industrial sector, which represents an annual growth of 0.6% since 1980 [121]. Surfactants are organic molecules that contain two functionalities with opposing characteristics [124126]. A surfactant contains both a hydrophilic (water-soluble) portion (polar) and a hydrophobic (water-insoluble) portion (nonpolar). When surfactants are dissolved or dispersed in water and/or nonaqueous solvents, the molecules will orient themselves in specific ways at the interface. One portion will align in the aqueous layer (hydrophile) while the other portion, the hydrophobe, is away from the polar portion of the system. This orientation of the molecule changes the surface properties of the system at the interface and is useful in many applications. Surfactant systems available are gasliquid, gassolid, liquidliquid, liquidsolid, and solidsolid. Examples of some commercial applications of these systems are (1) corrosion (gassolid or liquidsolid); (2) detergent (liquidliquid); and (3) slip agents (solidsolid). Fatty acid amides possess the characteristics necessary to function as a surfactant. The amide functionality is hydrophilic in nature, whereas the long-chain hydrocarbon backbone is hydrophobic.

< previous page

page_3

next page >


page_4

< previous page

page_4

next page >Page 4

The hydrocarbon backbone of fatty acid amides is derived from various animal fat and vegetable oil sources. Triglycerides of fats and oils are either split with steam at elevated temperatures to form a mixture of the component fatty acids, which serves as starting material for amide preparation, or the triglyceride is reacted directly with amines to form the fatty acid amide [127131]. For a good general review of the overall fatty acid industry (marketing, preparation, reactions, uses, etc.), see the abstracts of the 1987 short course offered by the Education Committee of the American Oil Chemists' Society [132]. Triglycerides used to prepare the wide range of fatty acid amides commercially available come from many sources. Typical compositions of the crude mixture of fatty acids prepared from the splitting of some animal fats and vegetable oils are given in Table 2 for tallow [132,133], coconut oil [134], soybean oil [135], cottonseed oil [136], sunflower oil [137], and palm oil [138]. Fatty acid composition will vary slightly depending on the region from where the crude fat or oil comes from. The composition will also vary slightly from year to year. Other fatty acids used in the preparation of fatty acid amides are stearic acid (C18), oleic acid (C18), behenic (C22, saturated), and erucic (C22, unsaturated) [139141]. II Synthesis and Purification Several reviews on the chemistry of fatty acids are available [2,128,133,142,143]. These reviews cover the preparation of fatty acid amides to some degree. A recent monograph, The Chemistry of Amides, contains a chapter, Chapter 2: Synthesis of Amides, dealing specifically with amide synthesis [144]. The monograph is an excellent review of the many synthetic pathways that are available for preparing amides. Many have been used to prepare fatty acid amides. This section is a review of the methods that have been used to prepare simple fatty acid amides and fatty acid amide derivatives of enhanced surfactant activity. In-depth reviews of the chemistry and properties of many of the fatty acid amides described are covered elsewhere in this book or in other monographs on the subject. A Fatty Acid Amides from Ammonia or Ammonia Derivatives Fatty acid amides are routinely prepared in industry by reacting fatty acids with ammonia or ammonia derivatives [128,132,143,145]. The simplest class of amides, primary amides, are prepared from the fatty acid by reacting with anhydrous ammonia at elevated

< previous page

page_4

next page >


page_5

< previous page

page_5

next page >Page 5

TABLE 2 Typical Fatty Acid Composition of Some Fats and Oilsa Starting fat or oilb Fatty Tallow Coconut Soybean Cotton- Sunacid seed flower 1.2 Caproic (C6:0) 3.415 Caprylic (C8:0) 3.215 Capric (C10:0) 4156 Lauric (C12:0) 3.0 1323 0.5 0.9 Myristic (C14:0) 29.2 4.212 712 25.24 6.24 Palmitic (C16:0) 19.1 1.04.7 25.5 2.69 4.14 Stearic (C18:0) 43.6 3.412 2050 17.53 19.76 Oleic (C18:1) 2.1 0.93.7 3560 52.55 69.50 Linoleic (C18:2) 0.5 213 Trace Linoleic (C18:3) 2.5 3 1 Other acids aData from Refs. 132 to 138. bThe fat and oil compositions are reported in percentages.

Palm

0.11.0 0.91.5 41.846.8 4.25.1 37.340.8 9.11.0 00.6 1

temperatures, 200C or above, for extended periods of time, as shown in Eq. (1):

An ammonium salt of the fatty acid is produced which upon removal of water (dehydration) is converted to the primary amide. Kita

< previous page

page_5

next page >


page_6

< previous page

page_6

next page >Page 6

et al. [146] have shown that decomposition of the ammonium salt at 50 to 70C forms the acid salt (RCO2H)2NH3. At temperatures over 150C, decomposition to amide occurs instantly. The reaction for producing amides appears to be first order for the acid from 135 to 200C [147]. The extended reaction periods for preparing fatty acid amides are shortened by using various catalysts during preparation. A common catalyst used is Al2O3 [132,148]. Metals of groups IVB and VB of the periodic table are found to be useful catalysts for the preparation of fatty acid amides [149,150]. In particular, titanium or zirconium alkoxides and esters are claimed to have good catalytic activity. Amination using copper(II)ammine complexes, [Cu(NH3) 4]SO4, as catalysts have also been used to prepare amides [151]. Monosubstituted amides (secondary amides) are produced by reacting fatty acids with primary amines (RNH2):

A wide variety of useful amides can be produced by reacting the acid with a fatty amine [141]. Reaction of fatty acids with secondary amines produce disubstituted amides:

An important class of amides used as surfactants is produced by reaction of a fatty acid with diethanolamine [2]. A more detailed discussion of the diethanolamine reaction is given in Section II.E. Reactions involving long-chain or highly branched secondary amines react slowly and will not go to completion. B Fatty Acid Amides from Triglycerides or Fatty Acid Esters Fatty acid amides have been prepared from triglycerides or fatty acid esters, usually the methyl ester:

Naser et al. described the reaction of various oils (triglycerides) with diethanolamine to prepare diethanolamide derivatives of the corresponding fatty acids [152]. The oils used in this study were soybean, linseed, castor, coconut, and rice germ. Ammonolysis of the oil was catalyzed by the use of various bases. Without a catalyst reaction temperatures of 150 to 200C and extended reaction times are necessary to promote the reaction [132]. It was found that the use of sodium methoxide as catalyst lowered the reaction

< previous page

page_6

next page >


page_7

< previous page

page_7

next page >Page 7

temperature and shortened the reaction time for preparing the amides while producing products with better color. Zinc oxide or lead oxide were found to be more active than sodium methoxide. Calcium and barium hydroxide were classified as weak catalysts for ammonolysis of oils. A study on the preparation of jojobamide and homojojobamide is an example of preparing amides from methyl esters [153]. The methyl ester of jojoba oil was first prepared from the triglyceride and then reacted with ammonium hydroxide in a sealed steel reactor. Yields were 94 to 96% when the reaction was run at 190C for 24 h. C Hydrolysis of Nitriles Amides can be prepared by hydration of nitriles as shown in Eq. (5):

This process is described in several use patents as being feasible for the preparation of amides from nitriles with up to 20 carbon atoms [154157]. A catalyst is used to promote the reaction. Metal hydroxides from groups IA and IIA of the periodic table, tertiary amines, quaternary ammonium salts, or quaternary ammonium hydroxides have been claimed to be active hydration catalysts for preparing amides [154]. Solid supported catalysts for the hydration of nitriles include metals from groups IB and IIB of the periodic table [155,156]. Manganese dioxide has also been used for converting aqueous solutions or aqueous emulsions of the nitrile to amide [157]. A biological hydrolysis process has been described for the preparation of amides from nitriles [158]. Amide is produced from hydrolysis of aqueous solutions of the corresponding nitrile when specific bacteria are present. To be feasible the process requires solubility of at least 1% of the nitrile. D Reaction of Fatty Acids or Esters with Polyamines Reaction products derived from the reaction of a fatty acid or ester with a polyamine (ethylenediamine, diethylenetriamine, trimethylenetetramine, etc.) produce important classes of surfactants used commercially in many industries. A brief synopsis of the chemistry is provided in this section. For an in-depth review of the use of these surfactants, refer to Chapter 2, Amidoamine Surfactants, and Chapter 3, Imidazoline Surfactants. Ethylenediamine reacts with a fatty acid (1:1 mole ratio) to form an amidoamine [143]:

< previous page

page_7

next page >


page_8

< previous page

page_8

next page >Page 8

The amidoamines prepared, now cationic in nature, are more useful surfactants than simple nonionic fatty amide surfactants. Used as is or with further modification, the amidoamines are utilized in the detergent area, as softeners, as shampoo additives, and so on (Chapter 2). Diethylenetriamine reacts with fatty acids or esters to form an amidoamine. Upon further reaction, by heating in vacuo to remove water, an imidazoline is formed [143,159]:

Imidazolines are available commercially for use as emulsifiers (cationic), flotation agents, softeners, and so on (Chapter 3) [160]. Reaction of 2 mol of a fatty acid or ester with ethylenediamine produces ethylenebisamides, as shown in Eq. (8):

If stearic acid is used, an important commercial material, N,N-ethylenebisstearamide (ethylene distearamide), is produced [141]. Ethylenebisamides are neutral, high-melting solids of low solubility in organic systems that find use as slip agents, mold-release agents, antiblock agents, defoamers, and paper chemicals, as discussed in Section VI. Methylenebisamides are prepared from primary amides and formaldehyde, with or without acid catalyst [143]:

Methylenebisamides have physical properties similar to ethylenebisamides and are used in the same application areas. E Ethoxylated Amides 1 Prepared from Alkanolamines Fatty acid alkanolamide surfactants are prepared commercially from alkanolamines, diethanolamine in particular, by reaction at elevated temperatures [161]. Alkanolamide surfactants are nonionic and

< previous page

page_8

next page >


page_9

< previous page

page_9

next page >Page 9

represent an important class of commercial surfactants (117 million lb/yr, 1980) [3]. For a list of the various trade names of commercially manufactured fatty acid alkanolamides, see McCutcheon's Emulsifiers & Detergents, p. 279 [160] and Section V. The chemistry of fatty acid alkanolamide surfactants has been reviewed extensively in the literature [2,127,162,163]. Reaction of a fatty acid or ester with diethanolamine is a complex reaction primarily because many side reactions occur due to the multiple functionality of the amine. Kritchevsky, in 1937, was the first to describe the reaction of a fatty acid with diethanolamine [164,165]. The reaction of 1 mol of diethanolamine with 1 mol of acid at 150 to 200C produces a product that is insoluble in water. However, using 2 mol of amine and 1 mol of acid a complex mixture is formed, mostly fatty acid alkanolamide (60 to 65%) but also containing esteramide mixtures, fatty acid salts, and diethanolamine, as depicted in Eq. (10):

The final product is a clear, brown, viscous liquid readily soluble in water (hydrophilic), with a pH of approximately 9. An improvement in Kritchevsky's alkanolamide synthesis was disclosed by Meade in 1949 [166], with further refinements described by Grossmann in 1975 [167]. Meade described the use of the methyl ester of the fatty acid as starting material and an alkanolamine (monoethanolamide or diethanolamine). It was found that in the presence of a basic catalyst, sodium methoxide, or more recently calcined CaO [168] or ZnCl2 [169], high-purity (>90%) fatty acid alkanolamides could be prepared at 100C with concomitant methanol removal:

High-purity fatty acid alkanolamides have been prepared in this manner from the methyl esters of lauric, myristic, palmitic, stearic, oleic, linoleic, erucic, and dimeric acids [170]. The alkanolamides are gels or solids at ambient temperature with minimal water solubility (hydrophobic). These high-purity alkanolamides are referred to as superamides [163]. Triglycerides have also been used for the preparation of superamides [170172], while the use of a-alkyl branched carboxylic acids produce an alkanolamide with a lower melting point than linear acids [173]. For a comparison of the two types of fatty acid alkanolamides, refer to Table 3. Kritchevsky-type amides are prepared using excess alkanolamines and fatty acid (2:1), while Meade-type amides are prepared using an equivalent amount of the alkanolamine and fatty ester (1:1).

< previous page

page_9

next page >


page_10

< previous page

page_10

next page >Page 10

TABLE 3 Alkanolamide Routesa Alkanolamide Kritchevsky type (%) route (regular) Fatty acid 6063.5 alkanolamide Ester-amide 123.5 mixture Alkanolamine 2329 Fatty acid salt 54

Meade type (%) (superamide) 9096 2.51.9 70.3 0.51.8

aData from Refs. 2, 163, and 167. 2 Prepared from Alkylene Oxides Ethylene oxide (EO) can be added to simple fatty acid amides to form alkanolamides [2,174176]. In the absence of catalyst, it would appear that both amide hydrogens could be substituted when a sufficient amount of EO is used, as is the case with primary amines. The addition of EO is usually depicted in stepwise fashion with the monoethanolamide the initial product. This is represented by Eq. (12) for the 1 mol of EO addition product:

The diethanolamide is formed after another mole of EO is added [2,143]:

In reality, evidence based on spectroscopic studies indicates that only one hydrogen of the amide is substituted [133,176179]. A catalyst is necessary to add EO (or propylene oxide) to a primary or an ethoxylated amide or to ethoxylate an alkanolamide [178,180]. Infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy have recently been used to study product makeup in various ethoxylation reactions [178]. In the absence of catalyst, the only reaction occurring after addition of EO at 170C was dehydration of the amide to nitrile. Addition of 1 mol of EO to primary amide in the presence of potassium hydroxide catalyst produces diethoxylated monosubstituted amide, 55%, with 45% primary amide remaining. As more EO is added, the primary amide is slowly used up while the

< previous page

page_10

next page >


page_11

< previous page

page_11

next page >Page 11

ethoxylated amide continues to add EO. Only one hydrogen is substituted even after the primary amide is completely used up (discussed further in Section III.F). Triethylamine, sodium methoxide, or potassium hydroxide, usually at high levels (1 to 10%), is used as catalyst with reaction temperatures of 120 to 170C to form a polyethoxylated amide from primary amide [180]:

Mixtures of ethoxylated (propoxylated) products are formed when using a diethanolamide, as shown in Eq. (15):

F Cationic Fatty Acid Amide Surfactants Cationic fatty acid amide surfactants are multifunctional compounds consisting of one or more substituted amide linkages and a quaternary ammonium salt. These products are prepared from amidoamines [181, Chap. 2]. The amidoamine used as a precursor for the quaternary can be prepared from the reaction of a fatty acid with amine, 3(N,N-dimethylamino)propylamine:

In addition to using a fatty acid, amidoamines can be prepared via a SchottenBaumann reaction, fatty acid chloride, and an amine, 2-(N,N-diethylamino)ethylamine [181]:

Quaternization of the amidoamine is usually done with either dimethyl sulfate, diethyl sulfate, or methyl chloride. Dialkyl sulfate quaternaries are easier to prepare than methyl chloride quaternaries. This is especially true if the amidoamine is highly branched, which is the case when polyamines are used. Brown described the preparation of a cationic amidoamine compatible with anionic surfactants [182]. The cationic surfactant is a composite mixture of the diethyl sulfate quaternary ammonium salts of cyanoethylated fatty acid amidoamines. Structures (1) and (2) show the reaction products described in the patent.

< previous page

page_11

next page >


page_12

< previous page

page_12

next page >Page 12

A commercial cationic fatty acid amide, Verisoft 222 (Sherex Chemical Company, Inc.), methylbis(tallowamidoethyl)-2-hydroxyethylammonium methyl sulfate, (3), is used as a fabric softener [183]. The diamidoamine prepared from diethylenetriamine is used as a starting material for this preparation. Quaternization of the ethoxylated amidoamine is readily accomplished using dimethyl sulfate.

G Anionic Fatty Acid Amide Surfactants An important class of commercially available anionic fatty acid amide surfactants used as detergent additives, is prepared by reacting a fatty acid chloride with N-methyltaurine, N-methyl-2-aminoethyl-1-sulfonic acid, as shown in Eq. (18) [133,143,184,185]:

The SchottenBaumann reaction is run using an aqueous solution of the sodium salt of N-methyltaurine. Fatty acid chloride is added to the aqueous solution while maintaining the pH at about 9 by the addition of concentrated sodium hydroxide. A final product is obtained which contains sodium chloride. It can be used as is or dried. The Igepon T series of surfactants, first described in 1931, are produced by the process described above. McCutcheon's Emulsifiers & Detergents, p. 164, lists the following Igepon T products as available from GAF Corporation [160]:

< previous page

page_12

next page >


page_13

< previous page

page_13

next page >Page 13

Igepon T33 Igepon T43 Igepon T51 Igepon T77 Igepon TC-42 Sodium N-(coconut acid)-N-methyl taurate Igepon TK-32 Sodium N-methyl-N-(tall oil acid) taurate Igepon TN-74 Sodium N-methyl-N-palmitoyl taurate N-Acylaminoalkane acids are another example of commercially prepared anionic fatty acid amide surfactants [185,186]. Sarcosine, N-methylglycine, a readily available synthetic amino acid, is a commonly used raw material in the synthesis of an N-acylaminoalkane acid, usually as the sodium salt. A fatty acid chloride is reacted in this one-step reaction with sarcosine to form the sarcosinate, as shown in Eq. (19) [187]: Sodium N-methyl-N-oleyl taurate

The sodium salt of the amino acid is used to promote the SN2-type reaction. Careful pH control is necessary to inhibit hydrolysis of the fatty acid chloride. A wide variety of N-acylamino acids have been prepared from various amino acids using this general synthesis [186]. Some commercial sarcosine products include: Closyl sarcosinates (Clough Chemical), Hamposyl sarcosinates (W. R. Grace), Hostapon sarcosinates and taurinates (American Hoechst), Maprosyl sarcosinates (Onyx Chemical Co.), and Sarkosyl sarcosinates (CIBA-Geigy Corp.) [160]. H Amphoteric Fatty Acid Amide Surfactants A recent comprehensive review (1982), Surface-Active Betaines, by R. Ernst and E. J. Miller, Surfactant Science Series, Volume 12: Amphoteric Surfactants (New York: Marcel Dekker), describes the chemistry, analysis, and physical properties of amphoteric compounds [188]. Included is a discussion on the preparation and activity of fatty acid alkylamidoalkylcarboxy and alkylamidoalkylsulfo betaines. As in the case with the preparation of cationic fatty acid amides, the fatty acid amidobetaines are prepared from amidoamines. Alkylamidoalkylcarboxybetaines are prepared by reacting an amidoamine with sodium chloroacetate [188,189]. The amidoamines prepared by reacting fatty acids with 3-(N,N-dimethyl)propylamine are

< previous page

page_13

next page >


page_14

< previous page

page_14

next page >Page 14

commonly used as the intermediates for synthesis of these complex molecules [161]. Refer to Eq. (16) for the synthesis of the amidoamine. Reaction of the amidoamines with sodium chloroacetate form alkylamidoalkylcarboxybetaines:

These compounds have been found to be very active as surfactants [188]. A patented process for preparing alkylamidoalkylcarboxybetaines describes the reaction of an amidoamine, prepared from a fatty acid and 2-(hydroxyethyl)ethylenediamine, with sodium chloroacetate [189]:

Careful pH control is necessary to prevent the hydrolysis of sodium chloroacetate to glycolic acid. Sodium hydroxide is added to neutralize the amine salt (betaine) formed and promote the reaction by making the amine more nucleophilic. Naik described the reaction of an alkenyl (C10C18)-substituted succinic anhydride with 3-(N,Ndimethylamino)propylamine to form alkylamidoalkylcarboxybetaines [190]:

These products are claimed to be useful as detergent additives. Alkylamidoalkylsulfobetaines are also prepared from amidoamines. The amidoamine, prepared from 3-(N,Ndimethylamino)propylamine [Eq. (16)], is reacted with sodium 3-chloro-2-hydroxyl-1-propanesufonate (epichlorohydrin/sodium bisulfite adduct) to form the corresponding alkylamidoalkylsulfobetaine, as shown in Eq. (23) [191]:

< previous page

page_14

next page >


page_15

< previous page

page_15

next page >Page 15

Nonbranched alkylamidoalkylsulfobetaines are prepared by reacting an amidoamine [Eq. (16)] with either chloroethanesulfonic acid salts, as shown in Eq. (24), or propanesultone, Eq. (25) [188,191]:

Reactions with these reagents are facile and products are formed in high yields at temperatures below 100C. A wide range of fatty acid alkylamidopropylcarboxy and alkylamidopropylsulfobetaines are commercially available. Coconut, lauric, myristic, palmitic, stearic, and oleic acids are examples of fatty acids used to prepare the betaines. The following is a brief compilation of some of the commercial fatty acid alkylamidoalkylcarboxy- and alkylamidoalkylsulfobetaines commercially available (see McCutcheon's Emulsifiers & Detergents for a complete listing) [160]: (1) Aerosol betaines (American Cyanamid), (2) Alkateric betaines (Alkaril Chemicals), (3) Amphosol betaines (Stepan Company), (4) Cycloteric betaines (Cyclo Chemicals Corporation), (5) Jortaine betaines (Jordan Chemical), (6) Lexaine betaines (Inolex Chemical Company), (7) Lonzaine betaines (Lonza, Inc.), (8) Mackam betaines (McIntyre Chemical Company Ltd.), (9) Mafo betaines (Mazer Chemicals, Inc.), (10) Maprolyte betaines (Onyx Chemical Company), (11) Mirataine betaines (Miranol Chemical Company, Inc.), (12) Monateric betaines (Mona Industries, Inc.), (13) Schercotaine betaines (Scher Chemicals Inc.), (14) Sipoteric betaines (Alcolac, Inc.), (15) Tego

< previous page

page_15

next page >


page_16

< previous page

page_16

next page >Page 16

betaines (Goldschmidt Chemical Corporation), (16) Varion betaines (Sherex Chemical Company, Inc.), and (17) Velvetex betaines (Henkel Corporation). I Purification of Fatty Acid Amides Fatty acid amides are purified by distillation in vacuo [192194]. Lichtenwalter and Carlson describe a process wherein the free acid in the amide is first neutralized with a base and then distilled through a molecular still [192]. The distilled amides are color stable with a color usually less than Gardner 1. A wide variety of bases can be used in the process and are selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, or organic quaternary ammonium hydroxides. As an example, industrial-grade stearyl amide (100 g), containing 3.98% free acids, was first neutralized with 4 g of a 25% solution of sodium methoxide in methanol. After stripping methanol at 150C and 1.0 mmHg, the amide was distilled through a wiped-film evaporator [190C (0.2 mm)] to yield 49 g of product with a Gardner color of less than 1. High-purity fatty acid amides with low color can also be prepared by distilling an amide prepared from a fatty acid decolorized with a hydrogenation catalyst (nickel, cobalt palladium, etc.) prior to amide formation [194]. Lightcolored products of Gardner 1 to 5 are obtained which are stable and lower in color than starting materials. No base is required in this process before distillation of the amide. III Analytical Methods This section briefly documents some of the analytical methods available for analysis of fatty acid amides and alkanolamides. For specific information on cationic [1, pp. 419448], anionic [195, pp. 141192], and betaine [188, pp. 97112] derivatives of fatty acid amides, see the references indicated. Data on chromatographic [gas chromatography (GC), high-performance liquid chromatography (HPLC), and thin-layer chromatography (TLC)] and instrumental (IR and NMR) methods of analysis have been published [170,176,196206]. These analytical methods have provided more precise information as to the makeup and chemistry of the amides (i.e., IR and NMR analysis data on ethoxylation of fatty acid amides). A Wet Methods Hydrolysis of amide to the corresponding free acid was used initially as a wet method of analysis for determining the purity of

< previous page

page_16

next page >


page_17

< previous page

page_17

next page >Page 17

fatty acid amides [176]. This analytical procedure is time consuming and problematic. A more convenient method for quantitative estimation of amide purity is described by Wimer [207]. The method is a direct titration of the amide with perchloric acid. In nonaqueous solvents (e.g., acetic anhydride), perchloric acid exhibits stronger acidic behavior than in aqueous systems and permits the titration of amides as bases. Endpoint is determined by potentiometric titration using a modified calomel-glass electrode. B Gas Chromatography Gas Chromatography (GC) of fatty acid derivatives has presented problems to the analytical chemist due to low volatility and a propensity toward decomposition at elevated temperatures. GC techniques and systems were developed which could separate the close-boiling homologs present in the products to be analyzed and at the same time eliminated the irreversible absorption of the sample on the GC column. Initial studies on GC separation of fatty acid amides involved reaction of the amide in situ, that is, formation of the fatty acid nitrile on the column, or prior conversion to a suitable derivative before GC analysis. These secondary derivatives were easier to handle and analyze [196]. Methods for the direct GC separation of fatty acid amides are described in the literature [196203]. By selecting the proper nonvolatile liquid phase for the column, good separation of the homologous amide mixture can be achieved. One of the first GC liquid phases to be developed for amide separation was a column with a polyester/phosphoric acid liquid phase [197]. This liquid phase gave good separation of oleylamide at 205C (5-ft column with 25% ethylene glycol succinate, 3% phosphoric acid on 60 to 80-mesh Chromosorb W). Other commercially available liquid phases have since been used, of which silicone packed columns are the most popular. Dowfax 9N9 with 2.5% sodium hydroxide [198], a polyamide, Versamid 900 [199], high-temperature greases such as Apiezon L [200], Dexil 300 GC (carboranesiloxane type) [196], and a 5% mixed cyanopropyl silicone liquid (2 parts of Silar 5-CP and 3 parts of Silar 7-CP) [201] have been described as liquid phases satisfactory for separating fatty acid amides by GC. Figures 1 to 3 are GC tracings of coco amide, tallow amide, and erucic amide, respectively, obtained using a 3-ft column of 1/8-in. stainless steel tubing packed with a mixed cyanopropyl silicone liquid phase on 100 to 120-mesh Chromosorb W AW DMCS treated [201]. A convenient GC method of analysis of fatty acid alkanolamides is reported by Calveras and Chico [202]. As indicated previously,

< previous page

page_17

next page >


page_18

< previous page

page_18

next page >Page 18

Fig. 1 GC tracing of coco amide, 230C. [From Ref. 201; reprinted with permission from C. N. Wang and L. D. Metcalfe, J. Am. Oil Chem. Soc. 61:581 (1984), copyright the American Oil Chemists' Society, Champaign, IL 61821.] the reaction of a fatty acid with alkanolamines results in a complex mixture of products (see Section II.E.1). Calveras and Chico describe the separation of the neutral fraction (esters) of a monoethanolamide preparation from the monoethanolamides by ion exchangers. Methyl esters of the fatty acids were prepared in this study as well as the mono- and ditrimethyl silyl ethers of the

< previous page

page_18

next page >


page_19

< previous page

page_19

next page >Page 19

Fig. 2 GC tracing of tallow amide, 230C. (Courtesy of C. N. Wang and L. D. Metcalfe, Akzo Chemicals Inc., McCook, IL 60525.) monoethanolamide fraction. GC analysis of both fractions is reported. For the monoethanolamide portion, a capillary column packed with Chromosorb G DMCS 80 to 100 mesh with 2.5% Silicone SE-30 from 100 to 300C was used to separate the mono- and ditrimethyl silyl ethers. A comparison of the GC data obtained on the two fractions is consistent with the fatty acid composition of the starting coconut fatty acid. A direct GC procedure has been described which is used to determine the purity of fatty acid monoamides of propanediamine-1,2 [203]. Analysis of the monoamides, prepared from the fatty acid ester and diamine, was carried out using GC columns with the following liquid phases and solid supports: (1) 15% Apiezon L on

< previous page

page_19

next page >


page_20

< previous page

page_20

next page >Page 20

Fig. 3 GC tracing of erucic amide, 250C. [From Ref. 201: reprinted with permission from C. N. Wang and L. D. Metcalfe, J. Am. Oil Chem. Soc. 61:581 (1984), copyright the American Oil Chemists' Society, Champaign, IL 61821.] Chromosorb W, (2) 10% Silikon XE-60 on Gas Chrom Q, and (3) 7% Apiezon L on Chromosorb G DCMS. The chromatograms obtained consisted of two peaks, which were the two structural isomers of the diamine (63:37 ratio). It is anticipated that the amide derived from the primary amino group would predominate. C High-Performance Liquid Chromatography Analysis of fatty acid amides by high-performance liquid chromatography (HPLC) has presented problems to the analyst because

< previous page

page_20

next page >


page_21

< previous page

page_21

next page >Page 21

of detector insensitivity to the compounds. However, ultraviolet and refractive index detectors have been used for HPLC work with fatty acid amides. Nakae and Kunihiro described the HPLC separation of homologous fatty acid alkanolamides [204]. A homologous series of fatty acid mono- and dialkanolamides with C10 to C18 alkyl groups were separated using a porous microspherical poly(styrenedivinylbenzene) gel, 10 to 15 mm, as stationary phase. An ultraviolet detector operating at 215 nm was employed to detect the eluting components. The recommended conditions for separating the homologs were to use a column 500 mm 4 mm ID with a mobile phase of watermethanol (3:97, v/v) at 30C. Fatty acid diethanolamides have been separated by HPLC using a Waters Associates unit coupled with a refractive index detector [170]. A fatty acid analysis column (30 0.39 cm) and tetrahydrofuranacetonitrilewater (100:135:105, v/v) solvent system at a flow rate of 1 mL/min provided good separation of individual components. D Thin-Layer Chromatography Thin-layer chromatography (TLC) is a convenient and quick way to determine the purity of fatty acid amides. This method, which is qualitative and inexpensive, can provide important information about chemical reactions and product makeup. TLC can separate functional groups in addition to a homologous series. TLC has been used to determine the purity of fatty acid diethanolamides. Separation of the fatty acid diethanolamides, prepared from the methyl ester of the fatty acid and diethanolamine, was carried out on Silica Gel G using chloroformmethanol (95:5, v/v) as developer and 10% phosphomolybdic acid as indicator [170]. A mixture of fatty acid monoamides of propanediamine-1,2 was analyzed by TLC using Silicagel G (Serva Entwicklungslabor) with a 10:5:1 mixture of benzene, methanol, and pyridine as developer, and ninhydrin detecting agent [203]. E Infrared Spectroscopy Infrared (IR) analysis is a useful method that helps one identify and characterize the structure of a compound. Functional groups exhibit characteristic absorptions in the IR region of the electromagnetic spectrum. Fatty acid amides have characteristic IR absorptions which are located in two areas of the IR region, the carbonyl (C=O) and the proton region (NH). Primary amides show a single absorption in the carbonyl region usually between 1680 and 1620 cm-1 [170,205,

< previous page

page_21

next page >


page_22

< previous page

page_22

next page >Page 22

206]. The carbonyl absorption is very strong and inteference from fatty acids, ketones, and esters can occur. NSubstituted amides will exhibit a second absorption in addition to the primary one. The second absorption usually occurs between 1560 and 1540 cm-1 [203, 205]. Proton NH stretching occurs at about 3545 cm-1 for primary (nonsubstituted) amides and 3429 to 3310 cm- 1 for monosubstituted amides [178,203]. Quantitative determination of small amounts of amides present in amines can be accomplished by measuring the carbonyl absorption (1680 to 1620 cm-1) and comparing the absorption to that of known mixtures [205]. In a similar manner, the proton NH stretch can be used to determine the amounts of primary amide and monosubstituted amide present [178]. This is illustrated in Fig. 4, the NH stretching region of a mixture of primary and monosubstituted amides. The bands due to the primary amide are 3540 and 3422 cm-1, while the band at 3455 is monosubstituted amide.

Fig. 4 IR tracing of the NH stretching region of a mixture of primary and monosubstituted amides. (From Ref. 178, courtesy of F. Mozayeni, Akzo Chemicals Inc., McCook, IL 60525.)

< previous page

page_22

next page >


page_23

< previous page

page_23

next page >Page 23

F Nuclear Magnetic Resonance Spectrometry Nuclear magnetic resonance spectrometry (NMR) is used in conjunction with the other methods of analysis mentioned previously to characterize further the structure of a fatty acid amide. Carbon-13 NMR can be used to determine whether a fatty acid amide is primary (nonsubstituted), monosubstituted, or disubstituted [178]. Chemical shifts in ppm from TMS for the carbonyl carbon will be approximately 175.9, 173.1, and 172.8, respectively. Substituted amides can be further characterized by the methylene carbon next to the nitrogen (CONHCH2-R, R = H or alkyl). For monosubstituted amides the 13C chemical shift occurs at 39.6 ppm, while for disubstituted amides the 13C chemical shifts appear at 48.2 and 46.1 ppm relative to TMS [178]. Vedanayagam et al. found the 13C chemical shift for the carbonyl carbon in diethanolamides to be between 174.9 and 175.3 ppm [170]. A 13C NMR tracing of a reaction product of 5 mol of EO with a simple amide is shown in Fig. 5. Chemical shifts of the 13C atoms relative to TMS are listed in Table 4 (note that only monosubstituted amide [CONH(CH2)] is formed, Section II.E).

Fig. 5 13C NMR spectrum of a 5-mol ethoxylate of a simple fatty acid amide. (From Ref. 178, courtesy of F. Mozayeni, Akzo Chemicals Inc., McCook, IL 60525.)

< previous page

page_23

next page >


page_24

< previous page

page_24

next page >Page 24

TABLE 4 Some 13C NMR Chemical Shifts of Ethoxylated Simple Amide

An attempt to characterize isomers of fatty acid monoamides of propanediamine-1,2 by proton (1H) NMR was not successful [203]. The long-chain fatty acid amides studied had very complex 1H NMR patterns. Separate signals for the amide proton for the two isomers could not be differentiated. IV Physical Properties Primary fatty acid amides are high-melting (68 to 108C) waxy solids with low solubility in water [176,177]. Solubility in typical nonpolar organic solvents (methyl ethyl ketone, chloroform, isopropyl alcohol, toluene, etc.) increases as the temperature is raised. Above 60C, solubility can vary from 10 to 100+%, depending on solvent and chain length of the fatty alkyl group [177,208]. Viscosity at 130C for the primary amides ranges from 4 to 6 centipoises with specific gravity averaging about 0.85 [208]. The amides are tan to brown in color (Gardner 4 to 8) and stable to air oxidation, heat, and dilute acid or bases when fully saturated [127]. Unsaturated primary amides with high iodine values (IVs) are susceptible to oxidation, leading to darker-color products. Typical physical properties of some primary fatty acid amides are listed in Table 5. Some monosubstituted (secondary) fatty acid amides are commercially available from Witco [208]. Table 6 lists typical physical properties of the monosubstituted amides. These amides are prepared by reaction of saturated and unsaturated fatty acids with saturated and unsaturated primary amines. Secondary amines have melting points lower than the corresponding primary amides from which they are derived even though there is a significant increase in molecular weight. The lower melting point can be attributed to loss of hydrogen bonding. Color of the monosubstituted amides ranges between Gardner 3 and 6, tan to brown. Solubility in water is low as with primary amides, usually 0.1% or less, but substitution of an alkyl group for a hydrogen increases solubility in organic solvents. This increase in solubility is especially evident at lower temperatures.

< previous page

page_24

next page >


page_25

< previous page

page_25

next page >Page 25

TABLE 5 Typical Physical Properties of Some Primary Fatty Acid Amidesa Amide mpb Solubilityc MWd Cocoamide 85 Page 28

and imidazoline derivatives, see McCutcheon's Emulsifiers & Detergents, p. 281 [160]. Cationic fatty acid amide derivatives are covered elsewhere (Chapter 3), while some anionic fatty acid amide derivatives are listed in Section II.G (taurates and sarcosinates). A list of commercially available amphoteric fatty acid amide surfactants is located in Section II.H, where alkylamidoalkylcarboxyl and alkylamidoalkylsulfo betaines are briefly discussed. As indicated, a wide variety of fatty acid amides are commercially available. The following tables, Table 9 (Primary Fatty Acid Amides), Table 10 [Monosubstituted (Secondary) Fatty Acid Amides], Table 11 (Disubstituted Fatty Acid Amides), and Table 12 (Alkanol and Ethoxylated Fatty Acid Amides), list the commercially available TABLE 9 Primary Fatty Acid Amidesa Amide Trade name Manufacturer Cocoamide Armid C Akzo Chemicals Inc. Stearamide Armid 18 Akzo Chemicals Inc. Armoslip 18 Akzo Chemicals Inc. (Hydrogenated- Armid HT Akzo Chemicals Inc. tallow)amide Armoslip HT Akzo Chemicals Inc. Akzo Chemicals Inc. Oleamide Armid O Akzo Chemicals Inc. Armoslip O Armoslip CPM Akzo Chemicals Inc. Armoslip CP Akzo Chemicals Inc. Erucamide Armoslip EXP Akzo Chemicals Inc. Oleamide Adogen 73 Sherex Chemical Company, Inc. Erucamide Adogen 58 Sherex Chemical Company, Inc. Stearamide Kemamide S Witco Corporation Oleamide Kemamide U Witco Corporation Kemamide O Witco Corporation Behenamide Kemamide B Witco Corporation Erucamide Kemamide E Witco Corporation aData from Refs. 139 to 141 and 177.

< previous page

page_28

next page >


page_29

< previous page

page_29

next page >Page 29

TABLE 10 Monosubstituted (Secondary) Fatty Acid Amidesa Amide Trade name Manufacturer Stearyl erucamide Kemamide E-180 Witco Corporation Erucyl erucamide Kemamide E-221 Witco Corporation Oleyl palmitamide Kemamide P-181 Witco Corporation Stearyl stearamide Kemamide S-180 Witco Corporation Erucyl stearamide Kemamide S-221 Witco Corporation aData from Ref. 208. products of Akzo Chemicals Inc. [139,177]; Akzo Chemicals GmbH [210]; C.P. Hall Company [209]; Emery Chemicals [212,213]; Lonza, Inc. [214]; Mazer Chemicals, Inc. [215]; Mona Industries, Inc. [211, 216]; Sherex Chemical Company, Inc. [140,217]; Stepan Company [218]; and Witco Corporation [141,208]. VI Applications A Lubricants Lubricants are substances that reduce friction, heat, and wear between two surfaces [4]. External lubricants are used to prevent sticking and lower wear due to friction of metal parts that are in contact with one another. TABLE 11 Disubstituted Fatty Acid Amidesa Amide Trade name N,N-Dimethylcaproamide Hallcomid M-6 N,NDimethylcaprylamidecapramide N,N-Dimethyllauramide N,N-Dimethyloleamide Hallcomid M 810 Manufacturer C.P. Hall Company C.P. Hall Company C.P. Hall Company C.P. Hall Company C.P. Hall Company

Hallcomid M-12

Hallcomid M 18OL N,N-Dimethylstearamide Hallcomid M-18 aData from Ref. 209.

< previous page

page_29

next page >


page_30

< previous page

page_30

next page >Page 30

TABLE 12 Alkanol and Ethoxylated Fatty Acid Amidesa Compositionb Trade name Manufacturer Alkanolamides Cocamide MEA Lauridit S Akzo Chemicals Inc. Lauridit LL Akzo Chemicals Lauric myristic acid MEA Inc. Cocamide DEA Lauridit KD Akzo Chemicals Inc. Lauridit VD Akzo Chemicals Fatty acid (1:2) Inc. polydiethanolamide Fatty acid DEA Lauridit LMD Akzo Chemicals Lauric myristic acid DEA Inc. Oleic acid DEA Lauridit OD Akzo Chemicals Inc. Cocamide MEA Emid 6500 Emery Chemicals Emid 6501 Alkanolamide DEA Emid 6560 Emery Chemicals Capramide DEA Emid 6544 (2:1) Emery Chemicals Emery Chemicals Cocamide DEA Emid 6514 Emid 6515 (1:1) Emid 6530 (2:1) Emid 6531 Emid 6533 Emid 6538 Emid 6731 Lauramide DEA Emid 6511 (1:1) Emery Chemicals Emid 6513 Emid 6519 Emid 6541 Emid 6590 Linoleamide DEA Emid 6540 Emery Chemicals Oleamide DEA Emid 6545 Emery Chemicals Emid 6547 (2:1) Soyamide DEA Emid 6548 Emery Chemicals Stearicoleic DEA Emid 6543 Emery Chemicals (continued)

< previous page

page_30

next page >


Documents

Document11