Aminolysis of polyesters for cracking and structure clarifying: A review

Abstract Cracking of polyester bottles and recycling the waste, which is of concern in the current research works have their roots in the environmental stress cracking and the physical structural analysis, which has been the subject of a huge number of research reports, that are collected in the present review. Polyesters are polymers of high importance in industry and academia, and amines are versatile chemicals that are used for different purposes. The reaction of polyester with amines has been used to reveal structure, improve the properties of products, convert polyesters waste into benign materials, enhance biocompatibility, and so on. The research works reported on the aminolysis of polyesters (PET, PCL, PLA, PTT, PBT, PHB, PEN, PEA) for structure and morphological determination, etching, and stress cracking are critically reviewed. The chemistry and mechanism of the reactions of aminolysis of an ester or a polyester are well documented, and a vast amount of useful information is available. There is a need for further research to answer the remaining questions on the intermediates. Solutions of amines act as environmental stress‐cracking agents, may induce crystallization, and probably it can dissolve and remove a certain amount of disordered regions as well. In the subject of stress cracking that can help the elucidation of the process of aging, it is not yet clear how cracks patterns and sizes (from nano up to micro size) observed on the surface of polyester products depend on the thermal and mechanical history of the samples, and it is not known how to produce cracked patterns according to a pre‐planned design on the surfaces of polyester articles. To make polyesters more useful and safe the structure must be revealed in order to get benefit from the structure–property relations.