氨基-铈盐氧化还原体系引发对苯乙烯磺酸钠在硅胶微粒表面的接枝聚合

Graft Polymerization of Sodium p-Styrenesulfonate on the Surfaces of Silica Gel Particles Initialized by Amino Group-Cerium Salt Redox System

使用偶联剂γ-氨丙基三甲氧基硅烷(AMPS)对微米级硅胶微粒进行表面化学改性,将氨基引入硅胶微粒表面,构成氨基-Ce(Ⅳ)盐氧化-还原引发体系。研究了在其作用下对苯乙烯磺酸钠(SSS)在硅胶微粒表面的接枝聚合,制得了具有较高接枝度(18g/100g)的接枝微粒PSSS/SiO2。采用FTIR、SEM及TGA等方法对接枝微粒进行表征。考察了对该表面引发接枝聚合体系接枝度影响的主要因素。结果表明,氨基-Ce(Ⅳ)盐体系可以有效地引发乙烯基单体在固体微粒表面的接枝聚合,氨基的质子化对产生自由基的引发步骤具有负影响;为提高PSSS的接枝度,引发剂溶液(铈盐+硫酸)宜采用滴加的方式加入;适宜的单体浓度为14(wt)%;接枝聚合宜在50℃下进行。接枝微粒PSSS/SiO2是一种功能复合微粒,凭借离子交换作用,对重金属离子和稀土离子均可产生强的吸附作用。

The graft polymerization of sodium p-styrenesulfonate （SSS） on the amino group-contained surfaces of silica gel particles modified chemically by 3-aminopropyltrimethoxysilane （AMPS） initialized by amino group- cerium salt redox system was realized, the 18g/100g of grafting degree of as-synthesized grafted particles PSSS/SiO2 was obtained. It indicated that amino group-cerium salt system can effectively initiate the graft polymerization of vinyl monomers on the surfaces of solid particles and protonation of amino groups will bring a negative effect to initiating. The optimum polymerization conditions of studied system were 14 （wt） % of monomer concentration and 50℃ of polymerization temperature, and to increase the grafting degree of the grafted particles PSSS/SiO2 , dropping process is an appropriate feeding way of the initiator solution.