METHOD OF MANUFACTURING POLYSTYRENE FOAM WITH POLYMER PROCESSING ADDITIVES

摘要

Disclosed is a method for making polystyrene foam which utilizes one or more atmospheric gases, particularly CO2, as the blowing agent in combination with a polymer processing aid (PPA), typically an ester that is relatively non-volatile at the extrusion temperature range. The blowing agent and the PPA may both be introduced into the molten thermoplastic polystyrene resin or the PPA may be incorporated in the solid source polystyrene resins. The resulting foam will be substantially free of residual blowing agent and dimensionally stable at ambient temperatures.

主权项

1. A method of manufacturing polymeric foam, comprising:
preparing a polymeric melt from a major amount of a polymer composition having a melt flow index of at least about 2 and a minor amount of at least one additive according the formula: wherein X is nitrogen or oxygen, and wherein R5 is selected from the group consisting of C1-C20 alkyl, aryl, alkaryl, and alkoxylate; injecting CO2 and one or more blowing agents into the polymeric melt to form a foamable mixture; and extruding the foamable mixture through a die into a region of reduced pressure.