Abstract:In order to improve the processing and mechanical properties of bismaleimide resin,eight novel types of bismaleimide monomers(hereinafter referred to as “bismaleimide monomers”) with structures containing rigid bisphenol fluorene(FDABMI),side group(PIDABMI),ether bond(34ODABMI),amide bond(34DABABMI and 33DABABMI),sulfone group(44DDSBMI and 33DDSBMI)and chain extension(BAPSBMI) were prepared,aiming to explore the structure-performance relationship of bismaleimide monomners with different structures.At the same time,diallyl bisphenol A(DABPA)was used as modifier to prepare bismaleimide resin by melting copolymeriazation with new type of bismaleimide monomers.The results show that the melting points of BAPSBMI and PIDABMI with extended chain structure and side methyl structure decreases significantly to 74 ℃ and 70 ℃,respectively.The glass transition temperature of the resin prepared by 33ODABMI and BDM is similar,about 250 ℃,while the bismaleimide resin prepared with the chain extension monomer BAPSBMI has the lowest Tg of 230°C. .The flexural modulus of 34ODABMI and 33DDSBMI are 4.1 MPa and 4.5 MPa,respectively,which are 14% and 25% higher than that of BDM.The results show that molecular structure design is closely related to performance, and the glass transition temperature of the resin is mainly related to the length of the bridging group in the bismaleimide monomer. The bismaleimide monomers with meta-substitution have higher flexural modulus.