焦磷酸络锰三价离子引发淀粉-丙烯酰胺的接枝共聚合

GRAFT COPOLYMERIZATION OF STARCH-ACRYLANIIDE INITIATED BY MANGANIC PYROPHOSPHATE COMPLEX

本文用焦磷酸络锰三价离子Mn(P_2O_7)_3^(-3)作为引发剂,制备了一系列丙烯酰胺—淀粉接枝共聚物(ST—g—PAM),比较了反应体系的酸浓度,单体和淀粉浓度,以及引发剂Mn^(3+)浓度对接枝共聚合的影响。体系的pH值大小对共聚影响最大。随体系PH值由小变大,接枝效率增加至一定程度后反而下降。在pH=3.3,引发剂浓度为1毫摩尔,单体浓度为0.6M/L和303K条件下,聚合转化率可达96%,接枝效率为95％。本文还对上述三价锰络合离子引发的ST—g—AM接枝共聚和在同样体系的AM均聚机理进行了讨论。

A series of starch-polyacrylamide graft copolymers (ST-g-PAM) were prepared by Mn^(3+)-initiated graft copolymerizations of acrylamide (AM) onto starch (ST) dissolved in water at 30℃. The effects of solution acidity and concentrations of monomer, starch and initiator on graft copolymerization were investigated.The copolymerization was much more susceptible to pH value of the reaction solution.Reaction mechanisms responsible for initiation of graft copolymerization and homopolymerization of AM were proposed and discussed.