Abstract: | Direct polycondensation of various nylon salts (salts of dicarboxylic acid and diamine) took place under mild conditions in the formation of polyamide in the presence of polyphosphates and organic bases. Among organic bases imidazole was the best in terms of polymer yields. The reactivity of the polyphosphates was arranged in following order: pyrophosphate ? tripolyphosphate > tetrapolyphosphate. Otimum reaction conditions were investigated in terms of solvents, temperatures, and concentration of monomers. A reaction mechanism was proposed for the phosphorylation reaction, due to polyphosphates, which led to the direct polycondensation of nylon salts. |