【摘要】 在纳米SiO2表面上进行聚对苯二甲酸丁二醇酯预聚物(pre-PBT)接枝改性,建立空间位阻稳定层, 提高了纳米SiO2的分散稳定性,增强了纳米粒子与树脂基体的相容性。红外光谱表明,接枝纳米粒子存在着 pre-PBT的酯基特征吸收峰,XPS的Si2p峰精细扫描表明二者形成了Si-O-C键,结合能降低;缩合聚合接枝体系的反应压力是影响纳米SiO2表面接枝量和接枝链长的重要因素,热失重分析和粘均分子量测定表明,随着反应压力的降低,热失重增加,接枝物分子量升高,接枝链变长;AFM观察表明在四氯乙烷中分散后的粒径约为50nm,几乎所有颗粒都以原生粒子的状态单独分散,颗粒间无团聚。SEN分析表明,接枝纳米粒子在聚对苯二甲酸丁二醇酯(PBT)树脂基体中可均匀地分散,二者界面间存在较强的界面作用。更多还原

【Abstract】 Steric hindrance layer can be established when the graft polymerization of PBT prepolymer was performed onto the surface of the nano-particles, which not only increases the dispersibility of the particles, but also improves the compatibility between the nano-particles and the resin matrix. The FTIR spectrum shows that the grafted nano-particles exhibit absorption peaks which are the characteristic of the ester groups in PBT prepolymer. The Si2p peak of the grafted nano-silica in the XPS spectrum indicates that the binding energy of Si2p has shifted to the low energy side, and Si-O-C bond has been formed between SiO2 and PBT prepolymer. Vacuum plays an important role in determining the grafting amount and the length of the grafted chains. The relationship between the vacuum and chain length was investigated by TG and Mv. The lower the vacuum, the longer the grafted chains, and thus the more the mass loss. The AFM image shows that the particles dispersed in tetrachloroethane are about 50 nm in diameter, and they were almost dispersed homogeneously as original particles without any agglomeration or adhesion. The SEM image of the nanocomposite shows that the particles dispersed homogeneously in PBT matrix, there are well adhered at the interface.更多还原