反相悬浮共聚合成聚丙烯酰胺的中试研究

以丙烯酰胺和丙烯酸钠为单体,采用反相悬浮自由基共聚的方法进行了合成阴离子型聚丙烯酰胺的中试研究 ,并得到了分子量达 1.45×10 7的超高分子量聚丙烯酰胺。比较了中试与实验室小试两种情况下聚合条件的不同 ,确定了原料丙烯酰胺中金属杂质铜和铁的含量 ,研究了原料丙烯酰胺在有机络合物乙二胺四乙酸二钠 (EDTA)存在下与丙烯酸钠的共聚 ,并研究了中试条件下一些因素如引发剂浓度、脱水时间对产品分子量和溶解性能的影响。结果发现 ,在聚合体系中加入占丙烯酰胺质量 0.025 %的EDTA能显著提高聚丙烯酰胺的分子量 ,在本实验条件下 ,引发体系K2S2 O8-NaHSO3 的最佳用量是K2S2O8、NaHSO3 分别占单体质量的 0.05 % ;并且还发现 ,随着脱水时间的延长 ,聚丙烯酰胺的分子量和溶解性能均呈下降趋势。

Study on the synthesis of anionic polyacrylamide under pilot-plant test by inverse suspension copolymerization

The synthesis of anionic polyacrylamide under the pilot-plant test by inverse suspension copolymerization of acrylamide and sodium acrylate was studied,and super high molecular weight(1.45×107)polyacrylamide was obtained.The conditions of polymerization under the pilot-plant test were compared with those under laboratory-scale test.The contents of foreign-metal impurities such as copper and ferrum in raw acrylamide were determined.The copolymerization of raw acrylamide and sodium acrylate was studied in the presence of organic complex compound ethylenediamine tetraacetic acid(EDTA), and the effects of several factors such as dehydration time,initiator concentration on the molecular weight and the dissolubility of polyacrylamide were studied.It was found that the molecular weight of polyacrylamide significantly increased by adding EDTA 0.025%(mass ratio to acrylamide),and the best concentration of K2S2O8 was 0.05%(mass ratio to monomer), so was NaHSO3. It was also found that the molecular weight and the dissolubility of polyacrylamide decreased with the increase of dehydration time.