Continuous Foam Extrusion of Rigid-rod Polyphenylenes

Abstract

A novel family of processable rigid-rod polymers with outstanding mechanical properties have been recently introduced (Parmax® Self-Reinforced Polymers (SRPs)). These materials, among other applications, are of interest in the field of high-performance, rigid structural foam. In this study, the foam processability of Parmax® SRP resin is investigated using a single-screw foam extrusion setup and butane as a blowing agent. The effects of die temperature (i.e. the foaming temperature) on the cell size, cell density, cell morphology, and volume expansion ratios are investigated. Blowing agent concentrations and their effects on foam creation are also examined. Microcellular Parmax® SRP foams with cell population densities on the order of 10⁹-10¹⁰ cells/cm³ and expansion ratios ranging from 1.5 to 2 are fabricated.