交联剂对无皂P(MMA-EA-MAA)种子聚合乳胶粒成孔的影响

采用完全无皂种子乳液聚合技术合成了粒径窄分布的P(MMA-EA-MAA)乳胶粒,通过对上述胶乳进行碱处理,制备出了具有空腔结构和多孔结构的聚合物乳胶粒,研究了交联剂的种类和用量对聚合过程、胶粒特性及胶粒结构形态的影响.结果表明,体系中加入交联剂后,单体转化率都有不同程度的提高;随交联剂用量的增加,乳胶粒粒径略有减小,交联剂用量较高时,乳胶粒粒径分布加宽;二乙烯基苯(DVB)的交联效率稍高于双甲基丙烯酸乙二醇酯(EGDMA);不加入交联剂及EGDMA用量低于0.5%时,处理后乳胶粒呈空腔结构,加入DVB及EGDMA用量高于1.0%时,处理后乳胶粒呈多孔结构,并且乳胶粒体积增量随交联剂用量的增加而减小.

高羧基含量无皂多孔聚合物乳胶粒的研究

功能性聚合物乳液的性能与其功能基的含量密切相关.采用完全无皂种子乳液聚合技术合成了具有不同羧基含量并且粒径分布均一的交联型聚甲基丙烯酸甲酯-丙烯酸乙酯因为甲基丙烯酸[P(MMA-EA-MAA)]乳胶粒,然后通过碱后处理,制备出了高羧基含量的无皂多孔P(MMA-EA-MAA)乳胶粒.系统研究了MAA对聚合反应、胶粒特性及胶粒多孔结构形态的影响.结果表明:在交联剂二乙烯基苯用量一定(0.3 g)的条件下,随着MAA用量从4.0 mol%增加到10.0mol%,聚合物交联程度(Px)从28.26%迅速增大至90.95%,当其用量超过10.0mol%后Px增大趋势变缓;随着MAA 用量的增加,处理后胶粒体积膨胀百分率(△V)逐渐增大,在MAA用量为12.0mol%时△V达到42.1%的最大值,当MAA 用量增大到14.0 mol%时,尽管Px高达95.44%,胶粒仍具有完好的孔状结构.

The structure and properties of Fe_3O_4/P (NaUA-St-BA) magnetic composite nano particles

Fe3O4/P （NaUA-St-BA） core-shell composite micro spheres were in situ prepared by soapless polymerization of styrene and butyl acrylate, with Fe3O4magnetic colloidal particles coated with NaUA. The results of IR and XRD analysis demonstrated that the desired polymer chains have been covalently bonded to the surface of Fe3O4 nano particles. The morphology analysis by TEM confirmed that the composite particles have the core-shell structure and a relatively uniform diameter of about 100nm. The magnetic properties of the obtained composite latex particles were measured by VSM and found that they exhibited super paramagnetic properties. Finally, the prepared magnetic composite particles latex is stable for several months.