根据曼尼期反应,在适宜的温度下,加入引发剂,使丙烯酰胺单体与丙烯酰氧乙基三甲基氯化铵阳离子单体发生自由基共聚反应,获得了阳离子聚丙烯酰胺高分子絮凝剂;系统地研究了共聚反应过程中单体总浓度、引发剂用量、聚合温度、pH值、增溶剂等因素对阳离子聚丙烯酰胺主要性能的影响,得出了最优反应条件-聚合温度为35℃,单体总浓度为20%,AM与DAC的相对摩尔比为6:1,复合引发剂为0.08%,pH值为7,增溶剂为2%,通入氮气时间为15min,反应时间为5h。在上述反应条件下合成了溶解性好、综合成本低、絮凝效果好、相对分子质量达3.00×10^6的聚丙烯酰胺产物。
According to the Mannich reaction, initiators were added at appropriate temperatures to acrylamide (AM) and dimethylamino ethyl acrylate methyl chloride (DAC) to initiate a free-radical co-reaction between AM and DAC and then to prepare cationic polyacrylamide (CPAM) macromolecular flocculant. The influences of such factors, as total concentration of monomers, use of initiators, copolymerization temperature, pH value and solubilizer on the main characteristics of CPAM in the process of the co-reaction were investigated, and the optimal reaction conditions were obtained as follows- copolymerization temperature 35℃, total concentration of monomers 20%, relative molar ratio 6 : 1, composite initiator 0.08%, pH value 7, solubilizer 2 %, time of ventilating nitrogen 15min, and reaction time 5h. Under the conditions above, a CPAM product with good solubility and flocculation property, low combined costs and molecular weight of 3.00× 10^6 was synthesized.