| 摘要 |
PURPOSE: To obtain a high-purity brominated polystyrene, assuming white color, excellent in resistance to thermal discoloration without causing the foaming and emitting a malodor when used as a flame retardant by heat-treating a powder of a specific brominated polystyrene at a temperature within a prescribed range. CONSTITUTION: A powder of a brominated polystyrene of the formula [(x) is 1.5-5; (n) is >=20] prepared by polymerizing a brominated styrene monomer (preferably having <=100μm particle diameter) is heat-treated at 120-200 deg.C temperature under <=200mmHg (e.g. 1-20hr) to afford the objective polystyrene of, e.g. >=99.5% purity. Furthermore, the powder is preferably obtained by carrying out, e.g. the solution polymerization of the brominated styrene monomer and then depositing the resultant polymer in a poor solvent.
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