在胶束溶液中铈盐引发制备双亲嵌段共聚物PSt-b-PVP及其表征

采用过氧化氢-硫酸亚铁的氧化还原引发体系,首先使苯乙烯(St)在乳液聚合体系中进行均聚合,制得了端羟基聚苯乙烯(PSt-OH),然后将PSt-OH增溶于十二烷基硫酸钠的胶束溶液中,在硫酸铈铵的引发作用下,使水溶液中的N-乙烯基吡咯烷酮(NVP)在PSt-OH端羟基部位发生嵌段共聚合,制得了双亲嵌段共聚物PSt-b-PVP。采用红外光谱(FT-IR)、核磁共振氢谱(1H-NMR)、凝胶渗透色谱(GPC)、差示扫描量热(DSC)等手段对嵌段共聚物的组成与结构进行了表征。结果表明:在Ce(Ⅳ)盐的氧化作用下,增溶于胶束中的端羟基聚苯乙烯端会在端基产生自由基,顺利地实现NVP的嵌段共聚合反应。随着共聚合时间的延长,共聚物PSt-b-PVP大分子链中亲水嵌段PVP的比例不断增大。

Preparation and Characterization of Amphiphilic Block Copolymer PSt-b-PVP by Initiation of Cerium Salt in Micellar Solution

The emulsion polymerization of styrene(St) was firstly carried out by initiating of H_2O_2-Fe~(2+) redox initiation system.PSt-OH was obtained with hydroxyl group as end group in polystyrene.Subsequently,the macromolecules PSt-OH were solubilizated in the micellar solution of sodium dodecylsulfate(SDS),and the block polymerization of N-vinylpyrrolidone(NVP) in the aqueous solution at the end group of PSt-OH was initiated by cerium ammonium sulfate,resulting in the amphiphilic block copolymer PSt-b-PVP.Sever...