聚合方法对一种正离子聚丙烯酰胺结构与性能的影响

对相同进料比下,以过硫酸胺/亚硫酸氢钠为氧化还原引发剂,分别用溶液法和反相微乳液法合成的丙烯酰胺(AM)与2-甲基丙烯酰氧乙基三甲基氯化胺(MADQUAT)的共聚物P(AM-MADQUAT),根据单体竞聚率计算了两种共聚物的序列分布和组成分布.考察了两种聚合物结构对高岭土絮体尺寸、zeta电位降以及絮体压缩屈服应力的影响,初步建立了不同聚合方法合成的阳离子聚丙烯酰胺结构与絮凝性能之间的相关性.

EFFECT OF POLYMERIZATION METHOD ON STRUCTURE AND PROPERTIES OF A CATIONIC POLYACRYLAMIDE

A cationic polyacrylamide was synthesized by polymerization of acrylamide and 2-(methacryloyloxy)-ethyltrimethylammonium chloride (AM/MADQUAT)in solution or by inverse microemulsion polymerization using (NH_4)_2S_2O_8/NaHSO_3 as redox initiator.The sequence distribution and composition distribution were calculated from monomer reactivity ratios of different polymerization methods.The results show that charge distribution is more uniform for the copolymer prepared in inverse microemulsion,and copolymer composition distribution is close to unity and maintains approximately at feed ratio.Furthermore,influence of the structure of cationic polyacrylamides on kaolinite flocs size,reduction of zeta potential and flocs compressive yield stress has been investigated at pH 7.The results show that the kaolinite flocs size is strongly dependent upon copolymer microstructure; with greater flocs size being observed for copolymer prepared in inverse microemulsion than for that in solution.Copolymer microstructure has a marked effect on the zeta potential,whose decrease in magnitude was much greater in the presence of copolymer prepared in inverse microemulsion than that in solution.Greater compressive yield stress was achieved for the strong flocs produced by copolymer prepared in inverse microemulsion.The difference in flocs compressive yield stress may be attributed to the flocs structure.Therefore,in this paper,a strong correlation between the cationic polyacrylamide structure and flocculation property for kaolinite suspension was established.