含氨基、羟基丙烯酸乳液聚合的稳定性

采用间歇及半连续乳液聚合方式,以过硫酸铵/亚硫酸钠为引发体系,合成了甲基丙烯酸甲酯/丙烯酸丁酯/甲基丙烯酸羟乙酯/甲基丙烯酸二氨基乙酯四元共聚物胶乳.系统研究了乳化剂种类和浓度、聚合温度、乳化单体进料方式及进料速率对聚合过程稳定性的影响.聚合温度降低,乳化单体进料速度减慢有利于聚合过程的稳定,采用种子半连续聚合方式比间歇聚合过程更稳定,乳化剂浓度的增加有利于聚合稳定性的提高和乳胶粒子的均匀化.

Stability of Emulsion Copolymerization of Acrylic Monomers Containing Amino and Hydroxyl Groups

The copolymer latex of MMA BA HEMA DMAEMA was prepared in the batch and semi continuous emulsion copolymerization process. The effects of emulsifier type and concentration, polymerization temperature and the feeding rate of emulsified monomer on the stability of polymerization were studied systematically. The results show that the HLB is not critical parameter for selecting the emulsifier used for the emulsion polymerization containing water soluble monomers. The available method for determining emulsifier system is still directly by the stability observation of the polymerization runs. The increase of functional monomer HEMA and DMAEMA content is beneficial to polymerization stability. The decrease of the polymerization temperature and the reduction of the feeding rate of the emulsified monomers are favorable to the stability of polymerization. The stability of batch polymerization is inferior to that of semi continuous polymerization for this system. The results also show that the increase of the emulsifier concentration will improve the stability of polymerization and uniformerize the particle size.