96 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Effect of Cosmetic Treatment/Sequence and Cycles of Chlorination on the Coefficient of Friction and Percent Stick of Blond Hair Pretreated Posttreated Cycles Treatment p• s* % Stick s p• s % Stick s 10 3O Control 0. 132 0.013 36.8 0.837 Bleach control 0. 194 0.015 39.2 0.837 Dye control 0. 184 0.040 36.8 1.304 Perm control 0.202 0.023 40.0 1.581 Control 0. 180 0.014 38.6 0.548 Bleach 0.266 0.026 43.2 2.280 Dye 0.222 0.008 39.6 1. 140 Perm 0. 194 0.013 38.2 1.304 Control 0.222 0.031 42.8 Bleach 0.268 0.024 40.2 Dye 0.280 0.065 39.0 Perm 0.214 0.021 43.2 Control 0.220 0.014 43.6 Bleach 0.310 0.027 41.8 Dye 0.254 0.019 37.0 Perm 0.246 0.013 44.6 0.254 0.019 44.0 0.236 0.184 0.015 43.4 0.894 0.248 0.013 44.0 1.732 3.033 2.387 0.256 0.025 43.6 2.702 1.581 0.220 0.022 42.0 2.236 1.095 0.264 0.013 49.2 5.263 1. 140 1.924 0.294 0.032 47.2 2.683 1.225 0.206 0.029 40.6 3.362 1.673 0.306 0.025 50.0 3.162 Control 0. 302 0.023 51.4 5. 597 Bleach 0.312 0.008 51.4 2.074 0.248 0.026 41.2 1.483 Dye 0.358 0.035 39.6 1.673 0.208 0.033 39.8 2. 168 Perm 0.312 0.023 46.2 3.701 0.272 0.016 48.2 3. 114 * s = standard deviation or five observations. When the cosmetic treatments followed chlorination, however, different trends were obtained. For the bleached and the permed samples, the average values of coefficient of friction increased with chlorination up to 15 cycles of treatment. These values were generally significantly higher than those of the control samples and either similar to or significantly higher than the values of the corresponding pretreated samples. For the postdyed samples, the values of coefficient of friction did not change much with in- creased chlorination and were consistently significantly lower than the corresponding values of the postbleached and postpermed samples. Similar results were seen for the percent stick parameter (Tables I and II). There was little difference between the percent stick values of the control samples and the pre- bleached and prepermed samples. Values generally increased with increased cycles of chlorination. In the postbleached and postpermed samples, percent stick increased up to 15 cycles of chlorination and then either decreased significantly (postbleached brown, postpermed) or remained relatively unchanged (blond, postpermed). In the dyed samples, the results of percent stick were inconclusive generally, there was little effect of cycles of chlorination or of treatment sequence. Examination of fibers in the scanning electron microscope showed little definite differ- ences in the morphology of the cosmetically pretreated and control fibers. The cosmetic

THE CHLORINE-HAIR INTERACTION 97 Figure la. Blond hair, untreated control. Figure lb. Blond hair, bleached only. Figure lc. Blond hair, dyed only. Figure ld. Brown hair, permed only.