偶联剂表面处理纳米SiC改性氰酸酯树脂的耐热性研究

Study on Heat Resistance of CE Modified by Nano-SiC Treated with Coupling Agents

采用模塑成型法制备氰酸酯(CE)/纳米SiC复合材料,通过热失重(TG)分析和动态机械分析(DMA),分别考察了小分子硅烷偶联剂KH-560和大分子硅烷偶联剂SCA-3表面处理纳米SiC对CE耐热性的影响。结果表明,两种偶联剂均能有效地提高其耐热性,在小于400℃的低温区SCA-3的改性效果优于KH-560,但在400～750℃的高温区相反,其耐热性的高低与复合材料储能模量(E′)有关;相对纯CE,纳米SiC的质量分数为1%时,经KH-560和SCA-3表面处理的纳米SiC改性的CE/纳米SiC复合材料的玻璃化转变温度提高率分别为16.71%和18.29%,质量保持率为95%的热分解温度提高率分别为17.25%和13.87%,450℃时质量保持率的提高率分别为59.67%和42.99%,E′≈1500 MPa时对应温度的提高率分别为16.03%和17.58%。

The CE / nano-SiC composites were made by moulding. Influences of the nano-SiC that was treated with silane coupling agent KH-560 and SCA-3 on the heat resistance of the composites were investigated through discussion of TG analysis and DMA. The results indicated that these coupling agents could both efficiently improve the heat resistance of the composites. When the temperature was 〈400℃, which was called low-temperature zone, SCA-3 did well in improving the heat resistance of the composites than KH-560. But the result turned out to be opposite in high-temperature zone, which was 400-750℃. The quality of the heat-resistant was related to the storage modulus（E）. Compared with pure CE, when the mass fraction of nano-SiC was 1.00%, the Tg of the composites respectively modified by KH-560 and SCA-3 had increased 16.71% and 18.29%, the heat-degradation temperature improved 17,25% and 13.87% when the mass loss of the composites was 5%, the quality maintaining rate separately increased 59.67% and 42.99% when the temperature was 450 ℃, and he temperature increased 16.03% and 17.58% when E＇ was about 1500 MPa.