| The bismaleimide resins are widespreadly used in the areas of aviation, airspace, mechanical and electronic industries because of their features such as thermal stability, insulativity, radioresistance, fire retardatory property, weather resisting property, good mechanical property and dimensional stability. In this work, methyl methacrylate(MMA), epoxy resin(EP) and unsaturated polyester resin(UP) were modified by industrial bismaleimides(BMD) and liquid crystalline bismaleimides to increase the thermal stability and mechanical property of the three materials. So the ranges of the three materials useness will be enlarged. The work has an important theoretical and practical senses.In this paper, a liquid crystal bismaleimide containing bisphenol-S group(Ia) and a bis[4-(4-maleimidophenoxy) phenyl]sulfone(SEM) have been synthesized and characterized by FT-IR, 1H NMR,DSC,HSPM. The spherulitic texture of nematic phase and good nematic liquid crystalline behavior can be observed by HSPM. Since Ia hasn't reported, this is the article′s innovation.Now most of the studies about modifying MMA thermal stability used N-cyclohexyl maleimide. In the paper, MMA was modified by SEM and BMD. The SEM-MMA binary copolymers and BMD-MMA binary copolymers in different ratios were prepared by bulk copolymerization. The results showed that the thermal properties of copolymers increased and the mechanical properties of these copolymers are the same as that of pure PMMA, which is the article's another innovation.The bismaleimide has the defects such as high melting point, bad resolvability, high curing temperature, great brittleness because of the structure, and these restrict its application and development. Industrial bismaleimides copolymers (BMDE) and liquid crystalline bismaleimide copolymers (IaE) are synthesized by using 4,4′-diaminodiphenyl ether (DDE) as chain extending reactants to improve some properties. The structure and liquid crystalline behavior are characterized by FT-IR and HSPM. The introduction of DDE has no effect on the liquid crystal behavior of Ia.The curing systems of E-51/amine modified by BMD, BMDE, Ia and IaE are studied. It is found that BMD and BMDE can improve the materials'impact strength and thermal properties. Compared with BMD and BMDE, Ia and IaE shows some advantages in the aspect of toughness, which may be attributed to special characters of liquid crystalline. The changes of materials'properties may be due to the change of the system's crosslink density and the chain rigidity between the crosslinked points.The thermosetting bismaleimide (BMD, Ia) and oligomers(BMDE, IaE) as a second component are introduced to unsaturated polyester resin respectively. It is found that BMD and Ia can improve the materials'strength and thermal properties, but Ia-UP system show some advantages in the aspect of thermal properties because of Ia's chain rigidity. BMDE can improve the materials'tensile strength obviously, and the tensile strength of BMDE-UP systems is improved 26% when the content of BMDE is 1%. IaE can improve the materials'tensile strength, impact toughness, bend strength. The mechanical properties are the best when the content of IaE is 0.5%.The non-isothermal curing kinetics of Ia-EP, IaE-EP, Ia-UPand IaE-UP are studied with DSC. The reaction heats and degrees of curing at different heating rates are evaluated. The reaction heats at different heating rates are close to a constant. The kinetic parameters, i.e. apparent activation energy Ea and reaction order n are presented based on Kinssinger and Crane equations. Apparent activation energy Ea as a function of curing degreeαis more than the constant activation nenergy.
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