SYNTHESIS AND CHARACTERIZATION OF POLYIMIDE-POLYOXYETHYLENE COPOLYMERS CONTAINING CARBOXYLIC-ACID FUNCTIONAL-GROUPS

A series of polyimide-polyoxyethylene copolymers have been prepared by varying the amount of polyamic acid and polyethylene glycol using sup er nucleophilic 4-dimethyl amino pyridine as catalyst by solution poly condensation. These copolymers have been characterized by GPC, intrins ic viscosity [eta], IR and NMR spectroscopy, differential scanning cal orimetry (DSC) and thermogravimetry (TG) analysis. The imidization tem perature was found to be dependent on copolymer composition and increa sed with an increase of amic acid content in the copolymer. Thermograv imetric analysis indicated a distinct two stage decomposition. X-ray d iffraction studies indicated long-range crystalline order for all the copolymers. Depending on the composition, all these copolymers showed an exothermic crystallization peak and an endothermic fusion peak in a ddition to the glass transition temperature (T-g). (C) 1997 Elsevier S cience Ltd.