Macromolecular compounds Communication 55. Application of interchain exchange reactions in linear polycondensation processes

Abstract

1. A study has been made of interchain-exchange reactions, reading to the synthesis of polyesters and polyamides, in compounds having amide and ester linkages. 2. It has been shown that, in presence of free hydroxyl, carboxyl, or amino groups, exchange reactions of the alcoholysis, acidolysis, or aminolysis types respectively occur at ester linkages. Amide linkages are broken only by amino and carboxyl groups; they are stable toward hydroxyl groups. 3. It has been found that no exchange reaction occurs between diethyl adipate and N,N′-hexamethylenebisacetamide in absence of catalyst; it occurs only in presence of an acid catalyst. 4. It has been shown that a narrow fraction of a polyester undergoes considerable change when subjected to prolonged heating: interchain exchange reactions occur, resulting in the formation of a more heterogeneous material, the distribution curve for which is similar to that of the original unfractionated polyester obtained by the polycondensation of adipic acid with ethylene glycol.