LATHERING POTENTIAL OF SURFACTANTS 231 80 SOG. Na Cocoyl _ •.• •........**, Sarcosinate 40 Na Cocoyl .e•'•?e•** •******- Na Myristo-Oil Sarcosinate • = Sarcosinate drain with Oi/ with time, •••• Myristoyl Sarcosinate .......' Na 0 0.3% 0.6% 0.9% 1.2% active Surfactant Concentration Figure 8. Lather drainage time versus concentration. sec. Na Lauroyl Sarcosinate with Oil I Sarcosinate • L.auramid=••e. .e •e Cocoamido ee* • Propyl Be•ine ß -•' • Pronyl Be•ine 60 drain time, 20 0 0 Na Lauryl Sulfate 1,0% active 1.0% active Test Surfactant 0 Figure 9. Lather drainage time for surfactant mixtures--sodium lauryl sulfate.

232 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 80 Na Lauroyl 60 Sarcosinate with Oil '•,•. Na •"••uroy• • '''-'• Sarcosinate 40 .**•' Cocoamido drain e•'*4 ,'/-- Propyl Betaine /•' with Oil time, • m J sec. mJl Cocoamido ß • **•' - Propyl Betaine 20 Lauramide• •'•..au ra mide 0 0 Ammonium Lauryl Sulfate 1.0% active 1.0% active Test Surfactant 0 Figure 10. Lather drainage time for surfactant mixtures--ammonium laury! sulfate. 80 sec. Na Lauroyl J ,• Sarcosinate with Oil Sarcosinate / Lauramide •' DEA with Oil $• • .. ...... ' .... ,........... Propyl Betaine • •='""='"='""=='=""='"='""" wifil Oil 60 drain time, 20 0 0 TEA Lau• ,I Sulfate 1.0% active 1.0% active Test Surfactant 0 Figure 11. Lather drainage time for surfactant mixtures--triethanolamine lauryl sulfate.