纳米SiO_2增韧增强氰酸酯制备工艺的研究

Preparing Process on Toughening and Strengthening Cyanate Ester with Nano-SiO_2

从纳米SiO2三种不同的分散工艺(研磨法、偶联剂表面处理法和高速均质剪切法)着手,通过原位聚合法制得SiO2/氰酸酯(CE)纳米复合材料;采用透射电镜分析(TEM)、扫描电镜分析(SEM)和热失重分析(TGA)研究了三种分散工艺对纳米SiO2的分散以及复合材料的力学性能和热性能的影响。结果表明,研磨对纳米SiO2的分散优于高速均质剪切,偶联剂表面处理分散较差;高速均质剪切对复合材料力学性能和热性能的提高程度优于研磨法,当纳米SiO2含量为1phr时,高速均质剪切所得复合材料的冲击强度和弯曲强度分别比纯CE提高35.0%和12.1%;当质量损失为5%时复合材料的热分解温度较纯CE提高23.8℃;偶联剂表面处理法则降低了复合材料的弯曲强度和热分解温度。

SiO2/cyanate ester（CE） nano-composites were prepared in situ polymerization, and three different methods of dispersing nano-SiO2 （attrition treatment, coupling agent surface treatment, high- speed homogeneous shearing） were investigated. Nano-particle dispersion, mechanical and thermal properties of nano-composites under three dispersing methods were characterized by transmission electron microscopy（TEM）, scanning electron microscopy（SEM） and thermogravimetric analysis（TGA） . The characterization results showed that attrition treatment produced nano-composites with more excellent nano-particle dispersion than high-speed homogeneous shearing, however, coupling agent surface treatment couldn＇t disperse SiO2 in nanometer size range. High-speed homogeneous shearing better improved mechanical and thermal properties of composites , and when nano-SiO2 was lphr （per hundred resin） ,the impact strength and the flexural strength of composites were respectively 35.0% and 12.1% higher than pure CE; and when the mass loss of composites was 5%, its degradation temperature improved 23.8℃ compared with pure CE. Coupling agent surface treatment decreased the flexural strength and degradation temperature of composites.