Process for the preparation of foams

摘要

The invention relates to a process for the preparation of foams by melting a thermoplastic, mixing the melt with a volatile blowing agent at a pressure of from 25 to 250 bar, decompressing the mixture to atmospheric pressure, and cooling the foam. The plastic used is a mixture of A) from 95 to 20% by weight of a styrene polymer and B) from 5 to 80% by weight of polyphenylene oxide. The resultant foams having high heat distortion resistance can be used as insulating materials.