分散聚合法制备聚丙烯酰胺水分散体

以丙烯酰胺为单体,采用分散聚合法制备了聚丙烯酰胺(PAM)水分散体。以PAM的相对分子质量和水分散体稳定性为指标,考察了分散介质类型、分散剂种类、引发剂种类及用量、单体含量、聚合温度、聚合时间和搅拌转速等因素对聚合反应的影响。实验结果表明,分散介质类型和分散剂种类是影响PAM水分散体稳定性的主要因素,选择乙醇-水为分散介质、聚乙烯吡咯烷酮为分散剂。采用正交实验确定了最佳合成条件:乙醇-水为分散介质(乙醇的体积分数为70%)、丙烯酰胺的质量分数为30%、引发剂偶氮二异丁腈用量为单体质量的0.3%、分散剂聚乙烯吡咯烷酮用量为单体质量的6%、搅拌转速200r/min、聚合温度80℃、聚合时间8h。在此条件下,可制得相对分子质量较高且稳定性较好的PAM水分散体。

Preparation of Polyacrylamide Aqueous Dispersoid by Dispersion Polymerization

Polyacrylamide(PAM)aqueous dispersoid was prepared by dispersion polymerization of monomer acrylamide.Effects of disperse medium type,dispersant type,type and dosage of initiator,monomer concentration,polymerization temperature,polymerization time,and stirring speed on relative molecular mass of PAM and stability of PAM aqueous dispersoid were investigated.The results show that medium and dispersant are key factors affecting stability of PAM aqueous dispersoid.Under optimal conditions obtained by orthogonal experiments: ethanol-water mixture as dispersion medium(ethanol volume fraction in the mixture 70%),dispersant polyvinyl pyrrolidone dosage 6%(mass fraction in acrylamide),acrylamide concentration 30%(mass fraction),initiator azobisisobutyronitrile dosage 0.3%(mass fraction in acrylamide),polymerization temperature 80 ℃,polymerization time 8 h and stirring speed 200 r/min,high relative molecular mass and stable PAM aqueous dispersoid can be obtained.