分散共聚合制备PSt-AA-EGDMA功能性单分散微米级交联微球的研究

以苯乙烯(St)为主单体,丙烯酸(AA)为功能单体,乙二醇二甲基双丙烯酸酯(EGDMA)为交联单体,聚乙烯吡咯烷酮(PVP)为稳定剂,偶氮二异丁腈(AIBN)为引发剂,乙醇/水混合溶剂为分散介质,用分散聚合法一步合成了功能性单分散大粒径(10～20μm)交联聚苯乙烯微球.研究了PSt-AA-EGDMA三元分散共聚合体系的动力学,由转化率-时间关联得到动力学方程;R_p=kI]^0.13(St]^1.87+AA]^0.13+EGDMA]^0.2)·(1+PVP]^0.2)exp(-E/RT).详细讨论了AA,EGDMA,PVP的浓度和溶剂极性对羧基分布的影响,阐述了AA和EGDMA对粒子形态、粒径及粒径分布的影响.

Studies on Dispersion Copolymerization of St-AA-EGDMA for Preparing Monodisperse Micron-size Functional Microspheres

Dispersion copolymerization of styrene(St), acrylic acid(AA) as functional monomer and ethylene glycol dimethacrylate(EGDMA) as the crosslinking monomer was carried out in ethanol/water mixture as the media by using poly(N-vinylpyrrolidone)(PVP), 2,2-azo-bisisobutyronitrile(AIBN) as the stabilizer and initiator, respectively. Monodisperse micron-size crosslinked polystyrene microspheres-containing carboxyl were directly prepared by one-step method of dispersion copolymerization. Polymerization kinetics was researched and kinetics formula, Rp=kI]0.13(St]1.87+AA]0.13+EGDMA]0.2)·({1+PVP]0.2)exp(-E/RT), was rendered. The effects of concentration of AA, EGDMA, PVP and solvent polarity on the carboxyl distribution were discussed in detail. The effects of concentration of AA and EGDMA on particle morphology, particle size and size distribution and carboxyl distribution were also researched.