ELIMINATION OF GELATINIZATION USING MIXTURE OF SOLVENTS IN THE ATRP REACTION TO SYNTHESIZE MULTI ARM STAR POLYMERS
利用混合溶剂消除ATRP反应制备多臂星形聚合物的凝胶现象

Hyperbranched polystyrene synthesized by the copolymerization of styrene and p-chloromethyl styrene was used as initiator to initiate the ATRP reactions of styrene and methyl methacrylate with CuCl/ pentamethyldiethylenetriamine as catalysts.The reaction dynamics were studied.It was found that the ATRP the reaction gelatinized easily in good solvent chlorobenzene.The monomer conversions before gelation were small.If poor solvent 1,4-dioxane was added in chlorobenzene before gelation,the gelatinization reactions could be eliminated efficiently.The monomer conversions could reach to high values and muti-arm star polymers with high molecular weight about a million were synthesized.This is new method to prepare multi-arm star polymers with high molecular weight.