功能化纳米SiO2-聚醚砜/BMI-酚醛环氧树脂复合材料的固化动力学与性能

以4，4’-二氨基二苯甲烷（DDM）为固化剂、双马来酰亚胺（BMI）和酚醛环氧树脂（F51）为基体、聚醚砜（PES）为增韧剂、硅烷偶联剂KH560功能化纳米SiO₂（KH-SiO₂）为改性剂，采用原位聚合法制备了KH-SiO₂-PES/BMI-F51复合材料，并通过非等温DSC确定了复合材料的固化工艺及固化反应动力学。根据Kissinger方程和Ozawa方程求得体系的表观活化能分别为96.03 kJ/mol和99.18 kJ/mol。FTIR测试结果表明:KH-SiO₂改性效果良好，不饱和双键和环氧基特征峰消失，BMI中C=C双键和F51中环氧基在DDM作用下参与了体系的固化反应。SEM结果表明:PES树脂和KH-SiO₂含量适当时，PES树脂和KH-SiO₂在树脂基体中分散均匀，断裂纹不规则杂乱发展，KH-SiO₂-PES/BMI-F51复合材料呈韧性断裂。力学性能测试和热失重测试表明:当PES含量为4wt%，KH-SiO₂含量为1.5wt%时，KH-SiO₂-PES/BMI-F51复合材料的弯曲强度、弯曲模量和冲击强度分别为156.23 MPa、4.18 GPa和20.89 kJ/m2，较BMI-F51基体分别提高了49.7%、29.4%和82.8%；KH-SiO₂-PES/BMI-F51复合材料的热分解温度为393.1℃，残重率为50%时，分解温度高达523.1℃，耐热性十分优异。KH-SiO₂-PES/BMI-F51复合材料的力学性能和耐热性有了较大提高，为拓展F51及BMI的应用范围提供了一定的理论数据。 

Curing reaction kinetics and properties of functionalized nano SiO2-polyethersulfone/BMI- phenolic epoxy resin composites

With 4,4'-diamino diphenyl methane (DDM) as the curing agent, bismaleimide (BMI) and phenolic epoxy resin (F51) as the matrix, polyethersulfone (PES) as the toughening agent and functionalized nano SiO₂ by silane coupling agent KH560(KH-SiO₂) as the modifier, the KH-SiO₂-PES/BMI-F51 composites were prepared by in-situ polymerization method, and the curing process and reaction curing kinetics were determined by non-isothermal DSC. The apparent activation energy of KH-SiO₂-PES/BMI-F51 composites are 96.03 kJ/mol and 99.18 kJ/mol according to Kissinger equation and Ozawa equation, respectively. The FTIR results reveal that the surface modification of KH-SiO₂ is favourable, the characteristic peaks of unsaturated double bond and epoxy group disappear, and the C=C double bond in BMI and epoxy group in F51 are involved in the curing reaction of KH-SiO₂-PES/BMI-F51 composites under the effect of DDM. The SEM images exhibit that PES resin and KH-SiO₂ uniformly disperse in the resin matrix when the content of PES resin and KH-SiO₂ are appropriate, the broken cracks develop irregularly and the material exhibits ductile fracture. The mechanical performances and thermogravimetric properties show that bending strength, bending modulus and impact strength of KH-SiO₂-PES/BMI-F51composites are 156.23 MPa, 4.18 GPa and 20.89 kJ/m², when the mass fraction of PES and KH-SiO₂ are 4wt% and 1.5wt%, which are 49.7%, 29.4% and 82.8% higher than that of BMI-F51 matrix, respectively. The thermal decomposition temperature of KH-SiO₂-PES/BMI-F51 composites is 393.1℃, and the temperature at the residual mass of 50% reaches 523.1℃, the heat-resistant property is excellent. The mechanical properties and heat-resistant properties of KH-SiO₂-PES/BMI-F51 composites are greatly improved, which provides theoretical data for expanding the application range of F51 and BMI.