交联PS微球表面PEMA刷子的合成与表征

Synthesis and Characterization of PEMA Brush Grafting from Crosslinked PS Microsphere

将含有双键的N,N二甲氨基甲基丙烯酸乙酯化学锚接在交联聚苯乙烯(PS)微球表面,再用过氧化苯甲酰引发甲基丙烯酸乙酯(EMA)氮氧调控自由基原位接枝聚合反应,将聚甲基丙烯酸乙酯(PEMA)接枝在交联PS微球表面,制备了PEMA刷子层;研究了聚合反应机理,并对所合成交联PS接枝PEMA共聚物进行了表征。结果表明,在2,2,6,6四甲基哌啶1氧自由基存在下,EMA的聚合反应为”活性”自由基聚合,所得到的PEMA摩尔质量分布在1.18～1.3范围,摩尔质量随聚合时间的延长而增大(9000～57000g/mol);红外光谱显示PEMA被接枝到了交联PS微球表面,交联PS微球粒径在0.5～1.2μm之间。

Poly（ethyl methacrylate）was prepared by means of in-situ grafting of ethyl methacrylate on a crosslinked PS microsphere backbone initiated by BPO in the presence of 2,2,6, 6-tetramethyl-1-piperidinoxyl （TEMPO）. The mechanism of the controlled free radical polymerization was studied and the grafted product was characterized. The experimental results showed that the grafting polymerization of ethyl methacrylate in-situ of crosslinked PS microsphere surface initiated by BPO in the presence of 2,2,6,6 -tetramethyl-1-piperidinoxyl （TEM- PO）was living free radical polymerization, the synthesized poly（ethyl methacrylate）had lower polydispersities （1.18 - 1.3）, the molecular weight could be controlled in the range of 9 000-57 000 g/mol.The FTIR result showed the poly （ethyl methacrylate）was grafted onto the crosslinked PS microsphere surface, and the particle diameter of the crosslinked PS rnicrospheres was in the range of 0.5-1.2μm.