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在N,N-二甲基乙酰胺/四氢呋喃(DMAc/THF)混合溶剂中,在正硅酸乙酯(TEOS)存在条件下,通过溶胶-凝胶法原位制备了聚醚酰亚胺(PEI)/SiO2复合材料.在该复合材料中,当SiO2含量低于20 wt%时,透射电镜(TEM)和扫描电镜(SEM)的观察表明,SiO2纳米粒子可以均匀分散,粒径可在80～300 nm间调控.差示扫描量热法(DSC)和热重分析(TGA)的结果表明,SiO2纳米粒子的引入使PEI的玻璃化转变温度(Tg)和热分解温度(Td)明显提高.将不同SiO2含量的PEI与环氧树脂及固化剂共混并固化,采用扫描电镜(SEM)研究了SiO2含量对体系相分离形貌的影响,结果表明SiO2纳米粒子的引入将使PEI分散相尺寸减小.动态力学分析(DMTA)和冲击测试的结果表明,使用PEI/SiO2复合材料改性环氧树脂,可以在提高韧性的同时达到提高模量的效果.
Polyetherimides were prepared in situ by sol-gel method in the presence of tetraethoxysilane (TEOS) in N, N-dimethylacetamide / tetrahydrofuran (DMAc / THF) PEI) / SiO2 composites.When the content of SiO2 is less than 20 wt%, the observation of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) shows that the SiO2 nanoparticles can be uniformly dispersed with the particle size of 80 ~ 300 nm.The results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed that the introduction of SiO2 nanoparticles significantly increased the glass transition temperature (Tg) and thermal decomposition temperature (Td) of PEI The effects of SiO2 content on the phase separation morphology of the system were investigated by scanning electron microscopy (SEM). The results showed that the introduction of SiO2 nanoparticles will make PEI disperse phase The results of dynamic mechanical analysis (DMTA) and impact test show that the use of PEI / SiO2 composite modified epoxy resin can improve the toughness while improving the modulus.