646 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table VIII Esters of Myristic Acid CHa(CH2)•2COOH C•4 Acid (Mol Wt 228) Approx Carbons on Viscosity Mol Wt Fatty Alcohol (Lotion)(cps) Branching Isopropyl Myristyl Hexadecyl Isostearyl Initial Slip (Scale 1-5) Myristyl 3.5 Isostearyl 4.0 Isopropyl 4.3 Hexadecyl 4.3 271 3 2276 5.6 448 14 24,700 ... 437 16 7150 19.5 479 18 7350 3.2 End Feel (Scale 4-20) Myristyl 16.3 Isopropyl 17.0 Hexadecyl 17.3 Isostearyl 18.3 Table IX Esters of Lauric Acid CHa(CH2)•0COOH C•a Acid (Mol Wt 200) Approx Carbons on Viscosity Mol Wt Alcohol (Lotion) (cps) Decyl laurate Hexadecyl laurate PEG 200 dilaurate PEG 400 monolaurate Initial Slip (Scale 1-5) PEG 400 monolaurate 2.0 PEG 200 dilaurate 3.0 Hexadecyl laurate 3.0 Decyl laurate 4.3 340 10 424 16 565 84- 582 17q- % Branching 6060 ... 7100 20.1 2208 ... 217 ... End Feel (Scale 4-20) Hexadecyl laurate 10.0 PEG 400 laurate 10.5 PEG 200 dilaurate 14.0 Decyl laurate 15.0 stearyl lactate (11.8). Although their molecular weights are theoretically identical, the two esters we tested differed slightly (as determined from actual saponification values), presumably due to different sources of raw materials. Oleyl lactate, also a C•s ester, gave an even higher End Feel score than isostearyl lactate. The two solid lactate esters gave only fair results, while all of the liquid lactates were excellent. A group of SATURATED FATTY ALCOHOLS was examined (Ta- ble XII). Here again, the pattern was similar: liquid alcohols gave better results than the solid ones. Furthermore, of the three liquid fatty alcohols evaluated, the two iso liquid fatty alcohols gave substantially

EMf)LLIENCY AND CHEMICAL STRUCTURE 647 Table X Esters of Adipic Acid HOOC(CH2)4COOH Co Acid (Mol Wt 146) Approx Carbons on Mol Wt Alcohol 174 2 884 .. 228 6 1382 .. 228 6 800 13 258 8 1080 .. 370 16 1000 16 810 30• 750 .. Dimethyl adipate Dipropyl adipate Diisopropyl adipate Dibutyl adipate Diethylhexyl adipate Di-PEG 350 adipate Initial Slip (Scale 1-5) Dimethyl 4.2 Dipropyl 4.4 Diisopropyl 4.5 Di-PEG 350 5.0 Diethylhexyl 5.0 Dibutyl 5.0 Viscosity •c (Lotion)(cps) Branching End Feel (Scale 4-20) Di-PEG 350 Dimethyl Diethylhexyl Dipropyl Dibutyl Diisopropyl 15.3 16.3 17.8 18.5 18.8 18.8 Table XI Esters of Lactic Acid CHaCH COOH I OH Ca Acid (Mol Wt 90) Approx Carbons on Viscosity Mol Wt Fatty Alcohol (Lotion)(cps) Branching Lauryl lactate 258 12 7800 Myristyl lactate 324 14 28,300 Cetyl lactate 310 16 25,000 Stearyl lactate 373 18 32,500 Isostearyl lactatc 353 18 5180 Oleyl lactate 356 18 4600 Linear alcohol lactate 276 (12-15 ) 7000 4.3 Initial Slip (Scalc 1-5) Steary[ Myristyl Cetyl Isostearyl Ct2-Ct, Oleyl Lauryl 3.0 3.7 4.0 4.0 4.0 4.8 5.0 End Feel (Scale 4-20) Stearyl Cetyl Lauryl Myristyl Isostearyl C•-C•, Oleyl 11.8 16.0 17.3 17.4 17.5 18.0 18.3