456 JOURNAL OF COSMETIC SCIENCE CATIONIC SURFACTANTS Tony O'Lenick Si/tech LLC, Dacula, GA Fatty quaternaries (quats) have been known for many years. Because of their fatty nature and positive charge, these compounds find application in a variety of areas including as conditioners for hair. Anyone that has added stearylalkonium chloride to sodium lauryl sulfate and observed the white sticky solid that results knows anionic and cationic surfactants can be incompatible. Anionic and cationic materials that produce a white gunky solid when mixed together are referred to as hard complexes. As the expression imp I ies the cationic and anionic compound possess properties which when added together form insoluble complexes (salts). We set out to determine if there are cationic materials having different structures which could be more soluble in the presence of anionic surfactants. The terms used here for quats and anionic materials are an adaptation of the work of Pearson used to describe acids and bases. Pearson proposed that "hard acids bind strongly to hard bases and soft acids bind softly to soft bases" 2 , the anionic and cationic interactions are exactly analogous. (Pearson R.G. Pearson, J Am Chem Soc, 85, 335 (I 963) The structural changes that can be made to cationic molecules can "soften" them, making them more compatible with anionic systems. The compatibility of specific quats with sodium lauryl sulfate (SLS) and sodium laureth-3-sulfate (SLES), the foam properties of the combinations with SLS and SLES and the substantivity of these combinations with SLS and SLES are key factors in understanding the function of conditioners.

Name AMB AME AMG AMM AEB AEG CaMB CaMG DMB DMG DMM MMB MMG MMM 2005 ANNUAL SCIENTIFIC SEMINAR The quats studied conform to the following st111cture· R2 I R'-N+-R1 er I R2 The preferred definitions for the study groups are· R1 I Alkyl (Cl2) 2 Ricinoleylamidopropyl 3 Dilinoleylamidopropyl 4 Cocamidopropyl R2 I. Methyl 2. 2-hydroxy ethyl R3 I. Methyl 2. Benzyl 3. Glyceryl Table I Co111pounds Studied R' R' Alkyl (Cl2) CH, Alkyl (Cl2) CH,CH20H Alkyl (CI2) CH3 Alkyl (CI2) CH, Alkyl (CJ2) CH2CH20H Alkyl (C12) CH2CH20H Castor Amido CH1 Castor Amido CH1 Dimer Amido CH1 Dimer Amido CH, Dimer Amid o CH1 Cocamido CH, Cocamido CH, Cocamido CH1 -CH1 -Clh-C6H, -CH2-CH(OH)-CH2-0H R' De�riotion Benzyl Coco dimethyl benzyl ammonium chloride CHJ Coco di-2 hydroxyethyl methyl ammonium chloride Glyceryl Coco dimethyl Glyceryl ammonium chloride CH1 Coco tri-methyl ammonium chloride Benzyl Coco di-2 hydroxyethyl benzyl ammonium chloride Glyceryl Coco di-2 hydroxyethyl glyceryl ammonium chloride Benzyl Ricinoleylamidopropyl dimethyl benzyl ammonium chloride Glyceryl Ricinoleylamidopropyl dimethyl glyceryl ammonium chloride Benzyl D1hnoleylamidopropyl dimethyl benzyl ammon1um chloride Glyceryl Dilinoleylamidopropyl dimethyl glyceryl ammonium ch.loride CH3 Dilinoleylamidopmpyl trimethyl ammonium chloride Benzyl Cocamidopropyl dimethyl benzyl ammonium chloride Glyceryl Cocam1dopropyl dimethyl glyceryl ammonium chloride CH1 Cocamidopropyl trimethyl ammonium chloride 457