摘要 |
<p>Expandable styrene polymer particles having reduced flammability are made by incorporating from 0.1 to 15 weight per cent of non-polymeric organic halogen compounds into the polymer during impregnation of the polymer particles with a blowing agent in aqueous suspension. Temperatures greater than 90.degree.C., during the impregnation step, often cause degradation of the halog compound and subsequent degradation of the polymer at the particle surface. The addition of certain hindered phenolic antioxidants, such as di-tert-butyl-p-cresol, stabilizes the halogen compounds in the suspension system to temperatures up to 125.degree.c.</p> |