Expandable Polyolefin with DSC double peak

摘要

Expandable polyolefin (I) showing a double peak in the DSC curve, contains 1-99 wt% polypropylene (A) and 1-99 wt% of a partly or completely crystalline polymer (B) which is incompatible with (A). Independent claims are also included for (1) a method for the production of (I) by mixing (A) and (B) with a blowing agent in an extruder and then extruding the mixture at a temperature and pressure such that no expansion occurs (2) polyolefin foam obtained by heating (I) with hot air or steam .