PolyHIPE块体中甲基丙烯酸甲酯的ATRP溶液聚合

将用高内相比乳液(HIPE)聚合法得到的多孔聚合物块体(poly HIPE)作为聚合的反应器,在其内部进行甲基丙烯酸甲酯(MMA)的原子转移自由基聚合反应(ATRP),通过扫描电镜、凝胶渗透色谱、红外光谱、热重分析、核磁共振和差示扫描量热等测试手段对块体内聚合的PMMA进行了分析测试。研究表明,MMA在poly HIPE块体内部按照ATRP聚合机理发生聚合;poly HIPE块体对MMA的ATRP溶液聚合影响不同于受限空间内部进行的传统自由基聚合及反向原子转移自由基聚合(RATRP);相较于普通的ATRP溶液聚合,块体内部ATRP聚合所得PMMA的数均相对分子质量有所降低,相对分子质量分布变窄,热稳定性有所提高,间同立构比例有所下降,但全同立构比例明显增加,玻璃化转变温度有所下降。

Solution Polymerization of Methyl Methacrylate in Polymerized High Internal Phase Emulsions by ATRP

A series of polymerized high internal phase emulsions (polyHIPEs) with different cavities and windows were used as reactors.Methyl methacrylate (MMA) was polymerized in the confined spaces of the polyHIPEs by atom transfer radical polymerization (ATRP).The resulting materials and PMMA in the polyHIPEs were characterized by SEM,GPC,FT-IR,TG,1H-NMR and DSC.The results indicate that the monomer MMA is successfully polymerized in the polyHIPEs by ATRP.The results are different from conventional radical polymerization and revise ATRP in the confined space.Compared with normal ATRP solution polymerization,the PMMA inside the polyHIPEs possesses a slight lower molecular weight and a narrower molecular weight distribution than those of the polymerization in the absence of polyHIPEs.The initial decomposition temperature of the PMMA increases significantly,while the glass transition temperature decreases,in addition,the proportion of syndiotactic PMMA decreases but isotactic PMMA increases.