反相乳液共聚合制备高分子絮凝剂工艺及产物性能

以丙烯酰胺（AM）和二烯丙基二甲基氯化铵（DMDAAC）为共聚单体，采用反相乳液聚合方法合成了高相对分子质量和高阳离子结构单元含量的共聚物絮凝剂（PDA），比较了不同种类引发剂和分散剂等对聚合过程的影响，优化了聚合体系。考察了单体配比、引发剂浓度和乳化剂含量等因素对单体转化率和产物相对分子质量的影响。采用傅里叶红外光谱（FT-IR）、核磁共振氢谱（1H NMR）和紫外可见分光光度计等对所得高分子絮凝剂进行了结构和性能表征。红外光谱、核磁共振氢谱和黏度测试结果表明，丙烯酰胺和二烯丙基二甲基氯化铵进行了共聚合反应并得到了高分子产物，且产物中二烯丙基二甲基氯化铵组分含量远高于相应条件下水溶液聚合产物。当DMDAAC]/AM]=1∶4、引发剂浓度为30mmol/L、乳化剂含量为18%时，产物黏均相对分子质量可达2.2×105，阳离子单元含量达17%。

Preparation and characterization of polymeric flocculant

Polymeric flocculant，owning high molecular weight and cationic unit content，was prepared by the inverse emulsion copolymerization of acrylamide（AM） and diallyl dimethyl ammonium chloride （DMDAAC）. The flocculation effect of poly（DMDAAC-co-AM）（PDA） was examined. The influences of types of initiator and dispersant on the copolymerization were explored. The effects of monomer ratio，initiator concentration and emulsifier content on the molecular weight of product and monomer conversion were studied. Fourier transform infrared spectrum（FTIR），nuclear magnetic testing（1H NMR） and ultraviolet spectrum were used to characterize the products. The results show that AM and DMDAAC did copolymerize，and the content of DMDAAC of the copolymer was much higher than that obtained by solution copolymerization. With DMDAAC]/AM]=1∶4，initiator concentration is 30mmol/L，and emulsifier content is 18%，the viscosity-average molecular weight of copolymer achieves 2.2×105，and the cationic units content is 17%.