Synthesis and structural studies of new copolyimides 2. Influence of pyromellitimide rings on copolymer structure

Abstract

AbstractThe reaction of pyromellitic dianhydride (1,2 : 4,5‐benzenetetracarboxylic dianhydride) (1) with L‐ and D‐alanine (2L) and (2D) leads to new monomers which were used to synthesize new copolymers. These copolymers were obtained as a product of the condensation of optical isomers of bis[N‐(1‐chloroformylethyl)]pyromellitimides (CFEP) with poly(ethylene glycol) PEG‐2000 (5). The effect of monomer structure on the structure and thermal properties of the polymers was studied using X‐ray diffraction, differential scanning calorimetry and thermogravimetry. The copolymers were compared with similar copolyimides obtained previously from bis(N‐chloroformylmethyl)pyromellitimide and poly(ethylene glycol), PEG 2000. The dominating effect of poly(ethylene glycol) comonomer on the crystallinity, structure and thermal stability of these new copolymers is proven.