非离子型可聚合聚氨酯/苯乙烯/甲基丙烯酸甲酯超浓乳液共聚合研究

Studies on PUASi-St-MMA Concentrated Emulsion Copolymerization

用甲苯二异氰酸酯(TDI)、聚丙醚二醇(PPG)、丙烯酸-β-羟乙酯(β-HEA)、二羟基聚硅氧烷(PSi)分三步制得非离子型可聚合的聚氨酯(PUASi),然后将PUASi溶于苯乙烯、甲基丙烯酸甲酯混合单体中,以十二烷基硫酸钠(SDS)、平平加(OS15)、聚乙烯醇(PVA-7188)作乳化体系,以偶氮二异丁腈(AIBN)为引发剂,在55℃下引发聚合。研究了乳化剂质量浓度、不同种类的乳化剂、引发剂质量浓度、内相比、聚合温度、PUASi与St的比例等因素对聚合稳定性及转化率的影响。用红外光谱对PUASi进行了分析,用透射电子显微镜(TEM)观察粒子的形态、用光相关光谱(PCS)测得了粒子的大小及粒径分布。

The PUASi was synthesized by using appropriate amount of 2,4 -diisocyanate （TDI）, polypropylene glycol （PPG）, 2 -hydroxyethyl acrylate （HEA） and polysiloxane （PSi） by three steps. Then, the PUASi was dissolved completely in mixture of St and MMA monomers, which is copolymerized using sodium dodecyl sulfate SDS, OS15, polyvinyl alcohol （ PVA - 1788 ） as composite emulsifier, and azobisisobutyronitrile （AIBN） as initiator at 55 ℃. The effects of emulsifiers＇ concentration, varieties of emulsifier, mass ratio of PUAG/St/MMA, initiators＇ concentration, volume fraction of the monomers phase （dp） and temperature on the stability of the concentrated emulsion and conversion rate were investigated. The morphol- ogy of polymer particles was observed by transmission electron microscopy （ TEM）, IR spectral results verified that PUASi copolymers were formed, and average size and the distribution of particle size was measured by photon correlation spectroscopy （PCS）.