122 JOURNAL OF COSMETIC SCIENCE Evaluation of DSC Isotherms: According to Table 9, there is a 2øC difference in the temperature for releasing loosely bound water molecules in the hair fibers. The difference in the three solutions is not statistically significant. Fiber Straightening Ability: The results of straightening ability of 1.325 M solutions of LiOH, NaOH, and KOH are shown in Table 4. The differences in the straightening ability of these three solutions are not statistically significant using this test method. However, NaOH may be slightly better than LiOH, and KOH in half head salon evaluation. CONCLUSIONS: Lithium, sodium, and potassium hydroxide solutions react with hair fibers differently. Lithium Hydroxide shows slowest tensile kinetics, least loss of tensile strength, swelling, and porosity. Potassium hydroxide appears to be the most damaging, as it has the fastest tensile kinetic rate, most F20 index loss, highest swelling peak, and the highest porosity imparted to hair. There appears to be no significant difference in the loss of loosely bound water from the hair fibers in all three solutions. There is no significant difference in the straightening ability of these alkali metal hydroxides. T•ble I. 2 -3 Figure I UOH NaOH KOH Average 0.92 0.93 0.91 Sl•ndard Deviator 0,01 0.01 0.01 Co-efficient of Variable 0.81 1.29 1.11 UOH NaOH KOH Average 7922 84.23 96.59 KINETIC STUDY OF EQUIMOLAR SOLUTIONS UOH VS. NaOH VS. KOH Standard Deviator 4.36 3.10 1.58 120,00 •- 20.0• ....... Table 0 Comparison of Water Uptake of Treated rs. Untreated Hair Water Uptake Untreated UOH NaOH KOH Average 30.7 42.79 46.42 46.06 Standard Deviator 0.55 0,45 0.09 0,79 Coefficient of Variable 1,79 1.25 0,20 1.53 T•Io 9 Peak Tempe•ltur• of Unb'eated and Treated Hair Fibres Peak T•mlx•ture Untr•ted UOH NaOH KOH Average 88.70 66.65 66.59 66.27 Standard Deviator 1.67 2.46 2.16 2.20 Coefficient of Variable 1.89 2.86 2.50 2.53 0 1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 TIME (mins.) I ---- liOH ß NaOH ß KOH I Figure 2 REAL TIME SWELLING OF FIBERS IN SOLUTIONS 160 • 20 0 1.5 3 4.5 6 7.5 9 11 12 14 15 17 18 20 21 23 24 Time (Minutes) ß UOH ß NaOH --•--KOH

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