CONDITIONING AGENTS 277 Table I Silicones Used in This Work and Their Abbreviations Name Structures Abbreviations (trade name) Dimethicones (polydimethyl- siloxanes) Dimethicone copolyols (silicone glycol copolymers) Amodimethicone (aminofunctional silicones) CH 3 CH 3 •H3 I I (KF-96) CHs- SiO4SiO•} • Si-CH 3 PDMS (SH200) ] x] ' x ] (TSF451) CH3 CH3 CH 3 (X-21-7501G) CH 3 CH 3 CH 3 CH 3 CH3-piO--•piO •piO)-- Si- CH 3 n I CH 3 CH 3 (CH2) 3 CH 3 O(C2H40)aH CH 3 CH 3 OH I I x CH 3 CH 3 (CH2) 3 NH(CH2)2NH 2 POES (SH377X) (KF6005) (X-22-4104) (X-22-4110) ADMS (SM8702C) the magnitude is dependent on the Mw of PDMS (the }x k with untreated hair is 0.18). The •L k values increase in linear relation to the Mw, but unexpectedly start to decrease when the Mw exceeds the value of approximately 2 X 10 4. PDMS with extremely high Mw (Mw exceeding 105) are especially effective in changing the lubricity of hair surface O. 20 0.18 0. 16 0.14 0.12 O. 10 104 lO s • of PI)• Figure 1. Effects of molecular weight of PDMS on the kinetic frictional coefficient of dry hair fibers.

278 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 0.6 0.5 0.4 0.3 0.2 0.1 dry i i i i I i I I 20 24 28 32 36 •'c (dyn/cm) Figure 2. Plots of kinetic frictional coefficient vs critical surface tension for dry hair: a, clean bleached hair b, clean normal hair c, n-C•sTAC d, n-C22TAC e, 2n-C•sDAC f, g-C28TAC (&, reference 1) g, PDMS (A). O. 20 O. 18 O. 16 ::l O. 14 O. 12 O. 10 10 2 10 a mount of P•lS depos i t ion ( # g/ghair as S i ) Figure 3. Effects of amount of PDMS (Mw = 22 X 104) deposition on the kinetic frictional coefficient of dry hair fibers.