R-ATRP of Acrylamide under the Action of Copper Complex System in Aqueous Two-Phase

Polyacrylamide (PAM) was synthesized by combining reverse atom transfer radical polymerization (R-ATRP) with aqueous two-phase polymerization. In aqueous two-phase system, polyethylene glycol 20000 (PEG20000) is used as dispersing agent, potassium persulfate (KPS) and Cu(en)2+ are used as initiator and control agent, respectively. In this paper the effect of monomer concentration, the amount of Cu(en)2+, reaction temperature, the ratio of Cu(Ⅱ), and ethylenediamine (en) were investigated. The experimental result shows the optimum conditions are as follows: m(AM)∶m(PEG)=1∶1, the monomer concentration is 10%, n(AM)∶n(CuCl2•2H2O)∶n(en)∶n(KPS)=3000∶10∶20∶1, polymerization time is 6 h, and polymerization temperature is 45°C. Under these conditions, the monomer conversion is 91.5%，the linear correlation coefficient is 0.9911.