硅烷偶联剂对聚甲基丙烯酸甲酯/二氧化硅纳米复合材料结构与性能的影响

Influence of silane coupler on structure and properties of PMMA/SiO_2 nanocomposites materials

采用乙烯基三乙氧基硅烷(WD-20)作为偶联剂,通过溶胶-凝胶法合成了聚甲基丙烯酸甲酯(PMMA)/二氧化硅(Si O2)纳米复合材料,采用紫外-可见光谱、红外光谱、扫描电子显微镜和热机械分析等研究了材料的结构和性能.结果表明,WD-20的加入对纳米复合材料透明性、耐热性能和微观形态结构有较大影响,随着WD-20用量的增加,纳米复合材料透明性增加,Si O2分散相尺寸变小,玻璃化转变温度增加.当WD-20与四乙基原硅酸盐(TEOS)之比为0·2时,所制备的纳米复合材料的溶胶分数为6%、玻璃化转变温度为250℃以上、可见光透过率在80%以上、Si O2分散相尺寸小于100nm.

PMMA/SiO2 nanocomposites were prepared in the presence of a silane coupler （WD-20） by the in situ sol-gel process. Furthermore, the effect of coupler content on the morphology and properties of the PMMA/SiO2 nanocomposites material was investigated by using UV-vis spectroscopy, FT-IR, SEM and heat distortion analysis. The results showed that, with WD-20 content increasing, the transmittance and glass transition temperature of the nanocomposites increased while the sol-fraction and the size of dispersed SiO2 phase in nanocomposites decreased. While the molar ratio of WD-20 and tetraethyl orthosilicate （TEOS） was 0.2, the sol-fraction of the prepared nanocomposites was 6%, glass transition temperature was above 250 ℃ and the transmittance was more than 80% at the wavelength between 450 nm and 800 nm and the size of dispersed SiO2 phase was less than 100 nm.