Synthesis and Properties of Novel Epoxy Resins by Radical Copolymerization of 2-Vinyloxyethyl Glycidyl Ether and N-Phenylmaleimide

Abstract

. To develop an epoxy resin having a high glass transition temperature and heat resistance, copolymerization of an epoxy group - containing vinyl ether and a maleimide derivative was carried out. Radical copolymerization of 2 - vinyloxyethylglycidyl ether ( VEGE ) and N - phenylmaleimide ( NPMI ) with AIBN were carried out in benzene or THF to give polymers having a molecular weight of 120,000 to 250,000 ( in case of benzene ) and a molecular weight of about 6,000 ( in case of THF ) in high yield, respectively. On the other hand, the copolymerization in the absence of AIBN hardly progressed in benzene, but in THF the polymers with a molecular weight of about 5,000 were obtained in high yield. 1 H NMR spectroscopy showed that the structure of the products is a copolymer composed of VEGE units and NPMI units. MALDI - TOF - MS spectroscopy revealed that the VEGE units and NPMI units are arranged mainly in an alternative manner. The glass transition temperature ( T g ) of the copolymers greatly varied depending on the copolymer composition and remarkably increased as the content of NPMI units increased. The thermal decomposition temperature ( T d ) of the copolymers was about 300 ° C or higher depending on the content NPMI units. By curing the reactive epoxy groups in the copolymers with multifunctional aromatic amines, novel heat - resistant epoxy cured resins with high T g were obtained.