Explanation

It is a method of preparing polymer foaming materials by using physical principles. It includes the following types: ① add supercritical fluid into molten polymer or its composite under pressure, then reduce pressure and temperature to release dissolved gas and form stable pores, and finally form stable bubble structure by cooling (down to below the melting point of polymer or glass transition temperature), commonly including C02 and N2 in supercritical state; ② Bubbles are formed by vaporization of low boiling liquid dissolved in polymer melt, commonly including halohydrocarbons, alkyl ethers, low-grade alkanes, low-grade alcohols and esters; ③ Porous polymer materials is formed by dissolving soluble components in polymer, such as salt powder; ④ The polymer foam materials is made by adding hollow spheres into the molten polymer and curing.

Classification