No abstract

Conditions were determined for selective alkaline transesterification of methyl 9(10)-carbomethoxystearate. With 2,2-dimethylpentanol and 2-ethylhexanol, the corresponding alkyl 9(10)-carbomethoxystearates were obtained in good yield. These two mixed alkyl diesters, along with other alkyl esters of mono-9(10)-, di-and tricarboxystearic acids prepared by conventional methods, were evaluated as lubricants. Several esters compared favorably with dioctyl sebacate used as the control. The esters had high viscosity indices and tow American Society for Testing and Materials slopes. The pour point of purified dimethylpentyt 9(10)-carbomethoxystearate is below -70 C. Several esters have antiwear properties when added to the control oil.

Summary A new method for hydroxylating long‐chain unsaturated compounds is described which involves addition of formic acid at its boiling point to the double bond followed by hydrolysis of the intermediate formate esters. The addition reaction proceeds slowly in the absence of catalysts, but strongly acidic substances, such as perchloric acid, sulfuric acid, and boron fluoride‐acetic acid complex, speed up the addition tremendously. Monohydroxystearic acids can be prepared in good yield by addition of 90–100% formic acid to the double bond of oleic or elaidic acids, methyl oleate, or the unreacted olefinic material separated from the hydrolyzed reaction product of oleic acid with formic acid, followed by hydrolysis. Similarly prepared are dihydroxyoctadecanes from oleyl alcohol, monohydroxyoctadecenoic and dihydroxystearic acids from linoleic acid, monohydroxyhendecanoic acids (isolated as methyl esters) from 10‐hendecenoic (undecylenic) acid, and secondary hexanols from 1‐hexene. Triglycerides are readily formylated if a small amount of mutual cosolvent is employed. Acetic acid in the presence of acidic catalysts also adds to the double bond at its normal boiling point, but yields are lower than with formic acid.

SynopsisCompositionally and structurally varied copolymers all containing n-octadecyl acrylate were prepared and evaluated as viscosity index improvers in a common base oil under conditions of low shear. Systems evaluated over a range of copolymer and blend composition were: copolymers of n-octadecyl acrylate with, respectively, methyl methacrylate, 2-ethylhexyl acrylate, and n-dodecyl acrylate; and homopolymers of poly(n-octadecyl acrylate), prepared with a wide range of molecular weights. Properties were compared with those of blends of commercial methacrylate copolymers (acryloids) which had been freed of their entraining liquid. Mixtures of base oil with copolymers of n-octadecyl acrylate and methyl methacrylate, compared at fixed SAE viscosities, were the most efficient of all blends studied. They had the smallest rate of change of viscosity with temperature (as measured by their ASTM slopes), particularly in the composition region of incipient polymer precipitation at room temperature. Efficiency of certain of these compositions was somewhat greater than that of the acryloids. A parameter that related concentration and weight-average molecular weight was used to correlate all of the data for ASTM slope and viscosity. Empirical relations developed by using this parameter enabled rheological data to be estimated that agreed within 6% of experimental values for the case of thermodynamically good base oil solvents. These data demonstrated the relatively small contributions of copolymer structure to viscosity index improvement.