| 摘要 |
A steam expandable alkenyl aromatic polymer composition and methods of preparation are provided. The composition is mixed with a volatile blowing agent containing, as a primary blowing agent, dichlorodifluoromethane and as a secondary blowing agent, a halogenated hydrocarbon, a hydrocarbon, or an aliphatic alcohol containing from 1 to 4 carbon atoms, the secondary blowing agent having a normal atmospherpic boiling point of from about 0 DEG to about 100 DEG C. The composition may be expanded by steam immediately after extrusion foaming or may be expanded after aging of the composition which has been impregnated with volatile blowing agent. |
