| 摘要 |
PURPOSE:To obtain highly crystalline polystyrene, by pretreating a catalyst by contact with a monomer other than a styrene, which forms a crystalline polymer, in polymerizing styrene by using a catalyst comprising a titanium halide and an organoaluminum compound. CONSTITUTION:A catalyst comprising a titanium halide (e.g., titanium trichloride) and an organoluminum compound (e.g., triethylaluminum) is pretreated by contact with a monomer which is other than a styrene and can form a crystalline polymer (e.g., propylene or 3-methyl-1-butene). This contact treatment is suitably performed in the presence of a saturated aliphatic hydrocarbon solvent (e.g., n-heptane), the treatment temperature is suitably a room temperature to 150 deg.C and, if required, a MW modifier such as hydrogen may be used. A highly crystalline polystyrene of a relatively large melting enthalpy is obtained by polymerizing styrene by using the catalyst subjected to the contact treatment.
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