SiO_2表面原位接枝聚环氧丙烷高分子刷的制备及表征

Preparation and characterization of polypropylene oxide polymer brushes grafted SiO_2 by in-situ polymerization

通过"Stober"法制备出单分散球形SiO_2粒子,并采用3-缩水甘油醚氧基丙基三甲氧基硅烷对其表面进行功能化修饰,然后,利用异丙醇铝作为多相催化剂,原位引发环氧丙烷(PO)单体开环聚合,制得了聚环氧丙烷(PPO)高分子刷接枝改性的SiO_2(PPO-g-SiO_2)。研究了单体添加量、反应温度及反应时间等因素对聚环氧丙烷高分子刷接枝量的影响规律。采用红外光谱(FT-IR)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)及热重分析(TGA)等分析方法对制备的PPO-g-SiO_2的化学结构、微观形貌以及接枝量进行了表征。结果显示,当单体添加量为2.38 mol·L^(-1),反应温度为80℃,反应时间为24 h时,PPO在SiO_2表面的接枝量可达23.56%(质量分数);其厚度约为15 nm。

Monodispersed spherical SiO2 particles were successfully prepared by Stober method, and the functional modification of SiO2 was obtained by the reaction of Si—OH with 3-glycidoxypropyltrimethoxysilane（GPS）. By using aluminum isopropoxide as a heterogeneous catalyst to initiate in-situ ring-opening polymerization of the propylene oxide（PO） monomers, a polypropylene oxide（PPO） polymer brush grafted SiO2（PPO-g-SiO2） was obtained. The effects of the amount of monomer, reaction temperature and reaction time on the grafted polymer brushes were discussed. In addition, the chemical structure and morphology of PPO-g-SiO2 and grafted amount were characterized by Fourier transform infrared spectroscopy（FT-IR）, X-ray photoelectron spectroscopy（XPS）, transmission electron microscopy（TEM）, scanning electron microscope（SEM） and thermogravimetric analysis（TGA）. The results show when the amount of the monomer addition is 2.38 mol·L-1, reaction temperature is 80℃, and reaction time is 24 h, respectively, the PPO graft quantity is up to 23.56%（mass） on SiO2 surface and the thickness is about 15 nm.