【作者】 欧宝立；

【导师】 黎华明；

【作者基本信息】 湘潭大学 ， 高分子化学与物理， 2005， 硕士

【摘要】 本论文采用甲苯-2,4-二异氰酸酯（TDI）对纳米二氧化硅粒子表面进行化学修饰合成功能化二氧化硅纳米粒子（SiO₂-TDI）;并在此基础上合成出二氧化硅大分子单体和原子转移自由基聚合（ATRP）二氧化硅大分子引发剂;再分别利用自由基共聚合和原子转移自由基聚合方法合成聚合物/二氧化硅杂化材料。主要研究工作包括以下几个方面: 采用两步法将可聚合的乙烯基单体键接到二氧化硅纳米粒子表面合成大分子单体。首先利用过量的甲苯-2,4-二异氰酸酯（TDI）对二氧化硅粒子表面进行化学修饰合成出表面带有高反应活性-NCO 基团的功能化二氧化硅粒子（SiO₂-TDI）,再利用SiO₂-TDI 与丙烯酸羟丙酯（HPA）反应将可聚合碳-碳双键引入到二氧化硅粒子表面合成出大分子单体。系统考察了反应条件对TDI 与SiO₂ 表面羟基反应的影响。此外,利用红外光谱（FTIR）和透射电镜（TEM）对大分子单体进行表征,TEM 结果表明SiO₂大分子单体能均匀地分散在甲苯中,没有发生明显团聚。利用SiO₂大分子单体分别与苯乙烯、甲基丙烯酸甲酯共聚合方法合成聚苯乙烯/SiO₂和聚甲基丙烯酸甲酯/SiO₂两种杂化材料。对聚合反应时间、单体投料比对共聚反应的影响进行了研究。此外用FTIR、TGA和SEM对杂化材料进行了表征,发现SiO₂粒子可以均匀地分散在聚合物基体中。以SiO₂-TDI 为原料,通过三步反应合成出ATRP 大分子引发试剂,然后采用ATRP 的方法合成出SiO₂ 表面接枝聚甲基丙烯酸缩水甘油酯（SiO₂-g-PGMA）和SiO₂表面接枝聚苯乙烯（SiO₂-g-PS）杂化材料。用TEM对表面接枝聚甲基丙烯酸缩水甘油酯的SiO₂粒子的形貌进行了观察分析;用FTIR、¹H NMR、GPC 对SiO₂表面接枝聚苯乙烯进行了表征。更多还原

【Abstract】 In this paper, silica-based macromonomer and macroinitiator were synthesized through the silica surface modifications. Polymer/silica hybrid materials were prepared by conventional radical copolymerization of silica-based macromonomer with styrene and methyl methacrylate, respectively. In addition, silica surface-grafted polymers were prepared using atom transfer radical polymerization (ATRP) initiated by silica-based macroinitiator. The main contents were as follows: Two-stage process has been developed to synthesize the macromonomer through surface-modification of silica with polymerizable vinyl groups. Firstly, the silica surface was treated with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into polymerizable vinyl groups by reaction with hydroxypropylacrylate (HPA). The main effecting factors on the reaction of silica with TDI were studied by determining the reaction extent of hydroxyl groups at the surface of silica particles. FTIR spectroscopy was employed to characterize the macromonomer. TEM images showed that the silica particles remained unaggregated after surface modification. The macromonomer have been used to copolymerize with vinyl monomers, i.e., styrene or methylmethacrylate, to prepare hybrid materials. The main effecting factors, such as ratios of vinyl monomer to the macromonomer together with the polymerization time, were studied by determining the extent of copolymerized vinyl monomer. The FTIR, TGA and DSC spectra were employed to characterize the hybrid materials. DSC results revealed that the glass transition temperatures (Tgs) of the hybrid materials were higher than that of the corresponding homopolymers. The distribution of silica particles in the hybrid materials was investigated by SEM, which showed that the silica particles were uniformly dispersed in the polystyrene matrix. Immobilization of the ATRP initiator on the silica surface was achieved in three consecutive steps. Poly(glycerol methyacrylate) and polystyrene chains were grafted from silica nanoparticles surface by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. TEM was used to observe the morphology of the poly(glycerol methyacrylate)/silica hybrid particles. FTIR, 1H NMR and GPC were employed to characterize the surface grafted-polystyrene.更多还原