Thermal Characteristics of Some Organic Esters

Abstract
Experience has shown that the principal limiting factor in the use of esters of organic acids as lubricants is the stability of these materials in a high-temperature environment. Comparisons of the thermal behavior of different types of organic acid esters have, in many cases, been made in all glass test equipment. A more comprehensive quantitative evaluation of the thermal reaction of these materials indicates a somewhat different relative behavior in systems containing metals. Analysis of the original ester and the product after thermal exposure using temperature-programmed gas chromatography allows one to determine the amount of ester degraded and to characterize the materials formed in the reaction. Materials investigated include dibasic acid esters, beta-blocked esters (polyols plus monobasic acids), and simple monobasic acid esters. A definite effect of catalyst metals in the system is indicated. The effect of the presence of metals is shown to differ with the type of ester. The critical nature of the alcohol group (beta carbon) is illustrated by several tests using methyl esters.