Preparation of low-density crystalline poly(ether ether ketone) foam by near-melting-point saturated supercritical carbon dioxide method

Abstract

This study focuses on preparing low-density crystalline poly (ether ether ketone) (PEEK) foam using near-melting-point saturated supercritical carbon oxide (sc-CO₂) method. Compared to conventional sc-CO₂ foaming technology, near-melting-point saturated sc-CO₂ foaming technology can achieve lower density due to saturation near the melting point, which reduces the crystal region and facilitates the dissolution and diffusion of physical foaming agents. The density of PEEK foam is closely related to resin characteristics and foaming parameters. Moreover, the density of PEEK foam hardly changed after being held at 305 °C for 10 h and after being placed in various media for 24 h, which indicated PEEK foam possessed outstanding high-temperature resistance and corrosion resistance. The above excellent properties of PEEK foam were due to high glass transition temperature, high melting point, and crystallinity of PEEK resin.