Process for the preparation of polyamides

摘要

Process for the preparation of polyamides comprising the steps of A) reacting a soybean oil condensate obtained from the deodorization of refined soybean oil and which contains less than 30% by weight of free and esterified oleic acid based on the total weight of free and esterified fatty acids in said condensate, with a C1-4alkanol in the presence of a zinc oxide catalyst to convert free fatty acids and fatty acid glyceride esters to fatty acid C1-4alkyl esters; B) removing excess C1-4alkanol, volatile reaction by-products, water, and the zinc oxide catalyst from the resulting reaction mixture; C) heating the reaction mixture from step B) under vacuum to obtain a distillate of fatty acid C1-4alkyl esters; D) separating the distillate from step C) into a fraction containing mostly C16-18saturated fatty acid C1-4alkyl esters and a second fraction containing mostly C16-18 unsaturated fatty acid C1-4alkyl esters wherein the oleic acid C1-4alkyl ester content is less than about 35% by weight thereof; E) dimerizing said second fraction in the presence of montmorillonite clay; and F) reacting the dimerized second fraction with a polyamine.