Foamable polymeric composition comprising propylene polymer and hydrated alumina

摘要

Compositions comprising propylene polymer, e.g., polypropylene, and hydrated alumina as filler precursor and sole blowing agent, wherein the alumina can be 30 to 60 weight percent of the total composition, are converted into foam having a fine and uniform cellular structure by passage through an unvented extruder at specified temperature profiles and pressures.