H2O2+Fe2+体系引发制备聚丙烯酰胺

实验采用水溶液聚合法,利用H2O2+Fe2+氧化还原引发体系引发聚合丙烯酰胺(AM),合成了非离子型絮凝剂聚丙烯酰胺(PAM)。利用正交实验确定最佳工艺条件为:AM质量分数20%,引发剂与单体(AM)物质的量比为0.0001,引发体系中氧化剂与还原剂物质的量比5:1,反应时间为8h,得到相对分子质量超过6.5×106的PAM。通过改变充入氮气方法、加入引发剂方法、改变还原剂物质的量比等工艺对实验进行了初步放大,得到了相对分子质量超过7.0×106的PAM,实验结果可重现。该聚合反应为一级反应,在20℃下聚合反应速率方程为ln[M]t=-0.0307t+0.3447。

Study on Preparation of Polyacrylamide With H2O2+Fe2+ Redox Initiation System

A nonionic flocculating agent polyacrylamide(PAM) was synthesized by the aqueous solution polymerization of acrylamide (AM) using H2O2+Fe2+ as redox initiation system. The optimal conditions of the polymerization were confirmed by the orthogonal experiment as follows: AM mass fraction of 20%, molar ratio of 0.001 for the initiator to the monomer of AM, molar ratio of 5:1 for oxidant of H2O2 to reductant of Fe2+ in the initiation system, reaction time of 8h. PAM with relative molecular mass of more than 6.5× 106 was obtained by the above process. PAM with relative molecular mass of more than 7.0×106 was prepared based on the primary enlargement of the experiment by changing method of pouring N2 and adding initiator as well changing molar ratio of reductants, etc. The experiment result can be repeated. The polymerization is the first order reaction, and its rate equation at 20℃ is expressed as ln[M]t=-0.0307t+0.3447.