Amino acids as substrates for preparation of monomers with imide rings

摘要

AbstractThe reaction of pyromellitic anhydride PMDA with some amino acids lead to monomers, which were used to synthesize new polymers. Application to glycine,D,L‐alanine and β‐alanine gave three bis‐acid chlorides. These are able to condense with glycols and diamines to yield a series of new copolyimides. Amino acids of two carboxylic groupsD,L‐glutamic acid andD,L‐aspartic acid gave, in reaction with PMDA, two similar dianhydrides (4) and (5). However, the condensation with aromatic amines lead to two different compounds. It was proved that, under the conditions studied, formation of hexa‐membered imide rings was impossible while penta‐membered imides formed without difficulty. Thermogravimetric analyses of these polymers were al