PRODUCTION OF LOW-MOLECULAR WEIGHT STYRENE BASED POLYMER

摘要

PURPOSE:To produce a polymer having improved thermal stability and desired low molecular weight at a low cost in a short time, by carrying out reaction under specific condition in homopolymerizing styrene or copolymerizing the styrene with other vinyl monomers. CONSTITUTION:Styrene is polymerized in the presence of hydrocarbons (e.g. toluene or ethylbenzene) or copolymerized with other vinyl monomers (e.g. vinyltoluene or methyl methacrylate) to produce a low-molecular weight styrene based polymer. In the process, the weight ratio of the hydrocarbons to the styrene or the styrene to the other vinyl monomers is 2-10 and a peroxide (e.g. benzoyl peroxide) or azo compound (e.g. azobisisobutyronitrile) having 0-70 deg.C lower half-life at 10hr (measured in 0.1mol./l concentration in benzene) than the polymerization temperature or both are used as a polymerization initiator so as to provide 100-280 deg.C polymerization temperature.