由大分子PMMA-DPE引发制备Poly(St-alt-MAn)微球

在1，1-二苯基乙烯（DPE）存在下，以甲基丙烯酸甲酯（MMA）为初始单体，偶氮二异丁腈（AIBN）为引发剂，采用本体聚合法制备出含有DPE片段的大分子引发剂PMMA-DPE；然后以PMMA-DPE 为引发剂，以苯乙烯（St）和马来酸酐（MAn）为共聚单体，乙酸异戊酯为溶剂,采用自稳定沉淀聚合法制备了单分散的聚（苯乙烯-马来酸酐）（Poly（St-alt-MAn））的微球。研究了 PMMA-DPE 的用量对聚合物微球的形态、粒径大小及分布的影响。采用 FT-IR, UV-Vis, 1H-NMR和 GPC 对产物的结构进行了表征，并用 SEM 观察了聚合物微球的形貌。结果表明，PMMA-DPE 能够引发 St 和 MAn 的共聚合，随着 PMMA-DPE用量的增加，聚合反应的转化率呈增大趋势，聚合物微球的粒径呈下降趋势，而粒径分布系数略有增大。

Preparation of poly (styrene-alt-maleic anhydride) microspheres initiated by the poly (methyl methacrylate) oligomer containing 1,1-diphenylethene units

Poly(methyl methacrylate)(PMMA) oligomers containing 1,1-diphenylethene(DPE) structural units(PMMA-DPE) have been prepared by the bulk polymerization of methyl methacrylate(MMA) in the presence of DPE with azodiisobutyronitrile(AIBN) as initiator.Narrow-disperse poly(styrene-alt-maleic anhydride) poly(St-alt-MAn)] microspheres were subsequently obtained by metastable precipitation polymerization of styrene(St) and maleic anhydride(MAn) initiated by the PMMA-DPE,with isoamyl acetate as solvent.The structure of the copolymer was confirmed by FT-IR,UV-Vis and 1H-NMR spectroscopy and GPC.The morphology and size of the microspheres were observed by SEM.The effects of varying the amount of PMMA-DPE on the morphology,particle size and size distribution of the microspheres were investigated.When the mass percentage of PMMA-DPE (based on total monomer amount) increased,the conversion increased and the diameter of the microspheres decreased,but the distribution of diameter increased slightly.