Study of Graft Copolymerization of Vinyl Acetate onto Acid-Thinned and Oxidized Starch(II)

Reaction of grafting copolymerization of vinyl acetate onto acid-thinned and oxidized starch using ammonium persulfte as initiator was investigated.The effects of mass ratio of monomer and starch on the graft copolymerization of starch were analyzed.With the aim of assessing the effects of reaction temperature and pH,on grafting percent ratio,grafting efficiency and monomer conversion efficiency during grafting copolymerization,temperature of grafting reaction and pH were varied based on a central composite design.The response surface analysis was used to determine the optimum level of the above mentioned operating variables.The results showed that when controlling mass ratio of monomer and starch,temperature of grafting reaction,and pH at 80%,70 ℃,and 4.0,the grafting percent ratio,grafting efficiency and monomer conversion efficiency could reach the maxmal levels of 28.2%,49.1%,and 99.8%,respectively.