New methods for the synthesis of polyesters and their oligomers


  • Presented at the IUPAC International Symposium on Macromolecular Chemistry, Moscow, June 1960.


Until recently the salts of iminoesters were prepared in general only from monofunctional nitriles and alcohols. In the papers published by us in 1959 we have shown that chlorides of imonium chlorides, produced by interaction between nitriles and hydrogen chloride in 1:2 molar ratios, will on reaction in the cold with equivalent amounts of primary alcohols give a high yield of imino ester hydrochlorides that in the presence of water will hydrolyze to the esters:

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An investigation into the mechanism of reaction between nitriles, hydrogen chloride and alcohols led to the synthesis of iminoesters using bifunctional reactants and thus to polyiminoester halohydrides and to the products of their hydrolysis, polyesters. The method developed differs from the conventional sysnthesis of polyesters in that it is based on a reaction heretofore not used for the synthesis of polymers. Moreover the reaction is carried out in the cold, whereas, ordinarily, elevated temperatures are used for obtaining polyesters. Depending upon the reactant ratio, from dinitriles, glycols, and hydrogen chloride new low molecular polyesters (M = 1000–1900) have been obtained with nitrile and alcohol terminal groups. First of all in the series of dinitriles and glycols containing aliphatic and aromatic radicals ω,ω′-dioxyalkyl esters of dicarboxylic acids have been synthesized. Owing the selective reactivity of the nitrile groups from bisadiponitrile besides the diols the heretofore unknown ω-oxyesters of δ-cyanovaleric acid and glycol di(δ-dicyanovalerates) have been obtained. The molecular weight of the polyesters was determined viscometrically and was calculated from the results of endgroup analysis. The results obtained in both cases coincided, which, in particular, indicates the practical absence of ring systems in the products.