环氧树脂改性双马来酰亚胺复合材料力学性能及耐热性能研究

STUDY OF MECHANICAL PROPERTIES AND HEAT RESISTANCE OF EPOXY RESIN MODIFIED BISMALEIMIDE COMPOSITES

为了探究环氧树脂(EP)对双马来酰亚胺树脂(BMI)的增强增韧效果,分别采用4种EP:AFG-90、TDE-85、E-14、D-17,用以改性BMI树脂基体,并同碳纤维方格布(CF)制成了CF/BMI-EP复合材料(CM)。采用差示扫描量热分析(DSC)测试了BMI和4组EP改性BMI的固化曲线和树脂固化后的玻璃化转变温度(Tg);采用傅立叶转换红外光谱仪(FTIR)测试了树脂体系固化后的红外吸收光谱;采用万能力学试验机测试了各组CM的弯曲性能和冲击韧性,观察记录了试样破坏的断裂形貌;采用扫描电镜(SEM)对CM试样的层间断面进行了形貌分析。研究发现,EP和BMI先后进行相对独立的固化,混合树脂相容性良好。实验发现,TDE-85的增强效果最佳,D-17的增韧效果最佳,并满足增强增韧规律。AFG-90、TDE-85、D-17改性BMI的Tg都在200℃以上,表明EP在改性BMI的同时并未牺牲耐热性。

In order to study the properties of epoxy （EP） resin modified bismaleimide （BMI） resins, four kinds of epoxy resin ： AFG-90, TDE-85, E-14 and D-17 modified BMI resins were prepared. BMI and EP modified BMI resins were processed into prepregs with carbon fiber （CF） grid cloth. The prepregs were made into composites through laminated molding. The infrared absorption spectrum of cured resin system was tested. The curing curves of unmodified and four EP modified resins and the glass transition temperature （Tg） was tested by DSC. The bending strength and impact toughness of the samples were test by a universal mechanical test machine. And the damaged morphology were observed and recorded by SEM. The results indicate that the EP and BMI are cured on different temperature with good compatibility. It was found that the enhancement of TDE-85 group was best, and the D-17 has the best toughening effect which fits the strengthing and toughing rules. The Tgs of AFG-90, TDE-85, D-17 were higher than 200℃, which suggests that EP modified BMIs did not sacrifice their heat resistance.