Preparation and properties of polymer alloys consisting of high-molecular-weight benzoxazine and bismaleimide

Abstract

Novel polymer alloys were prepared by blending a high-molecular-weight benzoxazine (HMWB) and a typical bismaleimide (4,4′-bismaleimidodiphenyl methane (BMI)) followed by thermal treatment up to 240°C. It was confirmed by the infrared and differential scanning calorimetric analyses that the phenolic hydroxyl group formed by the ring-opening polymerization of HMWB reacted with the double bond of BMI, in addition to the chain polymerization of the double bond of BMI and the ring-opening polymerization of HMWB. This further cross-linking through the formation of ether linkage made the polymer alloy films much more tough and flexible than each homopolymer film. Moreover, viscoelastic analyses and thermogravimetric analyses of the polymer alloy films showed that glass transition temperature and thermal stability also increased by alloying.