端环氧基硅油改性环氧树脂性能研究

采用端环氧基硅油及其预反应物来改性双酚A型环氧树脂。采用热分析、扫描电镜和力学性能等测试方法系统探讨了改性方法、有机硅含量对环氧树脂性能的影响。采用端环氧基硅油直接物理共混改性的EP，其耐热性几乎不变，但力学性能下降较大。采用5份端环氧基硅油预反应物改性的EP，其玻璃化转变温度由未改性的163.23 ℃提高到165.90 ℃，拉伸强度几乎保持不变，断裂伸长率由7.6 %提高到16.7 %，冲击强度由20.23 kJ/m2提高到27.19 kJ/m2。拉伸断面的SEM照片表明，环氧树脂固化物显示出明显的增韧效果。

Study on Epoxy-terminated Silicone Modified Epoxy Resins

Bisphenol A epoxy resin was modified by epoxy-terminated silicone. The impact strength, tensile strength, elongation at break, and glass transition temperature of the composites were investigated. The morphology of fracture surfaces was observed using SEM. The effects of modification methods and silicone content on material performance were discussed. After direct mechanical blending with epoxy-terminated silicone, the thermal resistance of epoxy resin was unchanged and the mechanical property declines clearly. When epoxy-terminated silicone was introduced via co-curing at 5 phr, the glass transition temperature of the system reached 177.35 ℃，which was higher than that of unmodified EP with 2.67 ℃. In addition to improved thermal resistance, the tensile strength almost remains unchanged and elongation at break increased from 7.6 % to 16.7 %, the impact strength increased from 20.23 KJ/m2 to 27.19 kJ/m2. A significant toughening was evidenced by the improvement of toughness and was supported by the SEM micrographs of the stretched section of cured epoxy resin.