j. Soc. Cosmet. Chem., 35, 339-343 (September/October 1984) Abstracts The Annual Scientific Meetings and Seminars of the Society of Cosmetic Chemists are important venues for informing the participants about the state of the art and recent technical advances in the field of Cosmetic Science. To provide broader dissemination of that information, the Publication Committee has decided to publish abstracts of the technical presentations made at these Meetings and Seminars in the Journal.--The Editor. Society of Cosmetic Chemists Annual Meeting December 6-7, 1984 Leszek J. Wolfram, Ph.D. (Clairol Inc.)and James Whittam, Ph.D. (Shaklee Corp.), Program Co-Chairmen SCIENTIFIC SESSION I HAIR PROPERTIES, PART I New insights into the structure and chemistry of human hair Helmut Zahn, Dr.-Ing, Deutsches Wollforschungs Institut, an der Rheinisch-West falischen, Tech- nischen Hochschule Aachen, West Germany For studies of hair's morphological components, cu- ticle, cortex, cell membrane complex, and melanin were isolated chemically and analyzed. The isodi- peptide gamma-glutamyllysine crosslinks proteins not only in the medulla but also in the cuticle. 92 single hair samples have been analyzed with the two-dimensional electrophoretic gel electrophoresis method of R. C. Marshall Mellbourne. Up to 62 isolated protein spots were found. Cosmetic treat- ments such as bleaching or perming make the pro- tein spots in the sulfur-rich region diffuse and weak. Internal lipids from the cell membrane complex were found in formic acid extracts as well as in wash liquors of thioglykolate-treated hair. The fracture behavior of negroid hair was studied to clarify the causes of fiber breakage at low levels of extension. Microscopic observation of the fiber reveals frequent twists, with random reversals in direction and high ellipticity along the length. Si- multaneous measurements of the effect of tensile load on extension and on the axial angle of un- twisting of specimens with a single twist indicate that failure at low extensions is due to the initiation of cracks at flaws near the twists, which relieves torsional stresses in these regions. Extension at failure is higher in wet fibers, probably because plasticization relaxes these stresses. Treatment of fibers with solutions of humectants such as poly- acrylic acid or glycerine has been found to reduce premature failure significantly. Scanning electron microscopy of fracture ends reveals a predominance of step fractures and fibrillated ends, indicating a large number of flaws, and poor cohesion between cortical cells. Fatiguing hair fibers seem to accen- tuate fiber damage and reduce intercellular cohesion in the cortex, leading to a predominance of fibril- lated fracture ends. Mechanical and fractographic behavior of ne- groid hair Y. K. Kamath, Ph.D., S. B. Hornby, and H. D. Weigmann, Ph.D., Textile Research Institute, P.O. Box 625, Princeton, NJ Relationship between triboelectric charging and surface modifications on human hair J. Jachowicz, Ph.D., G. Wis-Surel, and M. L. Garcia, Ph.D., Clairol Inc., 2 Blachley Rd., Stam- ford, CT 06922 339

340 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS The build-up of static charges on hair (phenomenon of fly-away) has been the subject of intermittent investigations. A directional triboelectric effect and a strong dependence on the humidity of the sur- rounding atmosphere were reported to be the main features of this process. Since triboelectrification is a surface phenomenon, it is sensitive to the chemical structure of the hair surface. The introduction of foreign species on the surface can strongly affect both the magnitude and the direction of electron transfer. The present communication describes the use of var- ious polymers and metals as contact probes to study the effect of surface modification on the triboelectric behavior of human hair. Measurements of both the sign and density of generated charges were con- ducted. The fibers were modified in various ways, including the adsorption of cationic polyelectro- lytes, monomeric or polymeric long alkyl chain quaternary ammonium salts, and the formation of polymer or polymer-detergent complexes on the surface. The primary effect of all these treatments is to alter the electrochemical potential of the fiber surface, and the occasional accompanying increase in electrical conductivity at 25-30% relative hu- midity appears to be of trivial importance. It was concluded that suppression of the static charge gen- eration can be achieved by reducing the difference in work functions between the contact probe used and the hair keratin. This can be done by the proper choice of comb material or the surface modification of the fiber. Factors affecting the kinetics of disulfide bond reduction in hair R. Randall Wickerr, Ph.D., and Bruce G. Barman, Ph.D., Procter & Gamble Company, Miami Valley Labs., P.O. Box 39175, Cincinnati, OH 45247 The kinetics of hair disulfide bond reduction by dihydrolipoic acid (DHL), dithiothreitol (DTT) and 1,3-dithiopropanol (DTP) and their analogues have been investigated using a single fiber technique. Structure activity relationships are described. It is shown that the overall rate of reduction may be altered by factors that affect the equilibrium con- stant of the reaction between the reducing agent and hair or the rate of diffusion of the reducing agent into the hair. Monothiol analogues of DHL are many times slower in reducing hair than is DHL which correlates with the much higher equilibrium constant of the reac- tion between DHL and hair disulfides. Reduction with DHL leads to the formation of a moving boundary of reducing agent in the hair. This boundary is clearly visualized by histochemical mi- croscopic techniques. Structure activity relationships in analogues of DTT and DTP illustrate the effects of hydroxyl groups on reactivity and differences between the formation of five-membered dithiolane or six-membered di- thiane rings on oxidation. SCIENTIFIC SESSION II HAIR PROPERTIES, PART II Connection between damage and electrostatic charge of hair fibers Peter Busch, Ph.D., Henkel KGaA,4 Dusseldorf, West Germany The generation of electrostatic charge by combing (or brushing) hair fibers not only leads to hair care problems ("fly-away phenomenon"), but also to marked hair damage. Owing to the opposite elec- trostatic charges, the hair fibers adhere to the sur- faces of combs or bristles of brushes and get stretched. The consequences of this stretching are: The hairs entangle, which causes high combing forces, and the hair surfaces get abraded, which leads to unfa- vorable hair-splitting values. The stress-strain be- havior of the electrostatically charged hairs, how- ever, is scarcely affected. "Self dynamic phenomena" play an important role in damaging the hair surface. The electrostatic influence was proven by specially developed measuring devices. Some particulars of the abrasion process are shown in cinematographic studies. The efficacy of several products will be ex- plained. Distribution of sulfur and crosslinking in hair Emory Menefee, 53 !3 Rosalind Ave., Richmond, CA 94805 The varying sulfur contents of mammalian keratins, including human hair, are not accounted for by as- suming that they have more or less of a matrix protein with uniform cystine/cysteine content. Rec- ognition in recent years of the presence of an "ultra- high sulfur" fraction suggests that perhaps a linear combination of three components may account for most of the variation. This is borne out by calcu- lation of the composition of a normal human hair and a trichothiodystophic human hair from fraction compositions taken from wool analyses. It is still speculative at present whether such fractions rep- resent components in situ or are somewhat artifac- rive. Furthermore, even for fibers with similar sulfur content, differences in crosslinking distri- bution among intra- and inter-molecular crosslinks can profoundly affect physical properties.