OXYGENATED HYDROCARBON COMPATIBILIZING AGENT FOR CARBON DIOXIDE-BLOWN POLYOLEFINIC FOAMS

摘要

A method of making a polyolefinic foam composition comprising the steps of: (a) feeding a polyolefinic polymer into an extruder; (b) adding a nucleating agent to the resin feed; (c) optionally adding a permeation modifier to the resin feed; (d) plasticating the mixture in an extruder to form a polymeric melt; (e) incorporating a blowing agent of carbon dioxide and optionally one or more members selected from the group consisting of inorgnaic blowing agents, organic blowing agents, and combinations thereof; (f) incorporating at least one compatibilizing agent into said foamable composition wherein said compatibilizing agent is an oxygenated hydrocarbon that decreases the minimum pressure required to prevent prefoaming while retarding the collapse of foam due to excessive blowing agent migration; (g) uniformly mixing and cooling the foamable composition to a temperature effective for the expansion of the polyolefinic foam; and (h) extruding or ejecting the foamable composition through a die to form a polyolefinic foam.