Semi-crystalline polymer-ceramic core-shell particle powders, and processes for making and articles comprising such powders

Abstract

Semi-crystalline polymer-ceramic composites and methods. The ceramic-polymer composites, in powder and/or pellet forms, comprise a plurality of core-shell particles, where: each of the core-shell particles comprises a core and a shell around the core; the core comprises a ceramic that is selected from the group of ceramics consisting of: AlO, ZrO, and combinations of AlOand ZrO; and the shell comprises a semi-crystalline polymer selected from the group of semi-crystalline polymers consisting of: polyphenylene sulfide (PPS), polyaryl ether ketone (PAEK), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), semi-crystalline polyimide (SC PI), and semi-crystalline polyamide (SC Polyamide). The core-shell particles can be in a powder form (e.g., a dry powder). In pellet form, shells of adjacent core-shell particles are joined to resist separation of the adjacent core-shell particles and deformation of a respective pellet. Methods of forming a ceramic-polymer composite comprise: superheating a mixture of the semi-crystalline polymer (PPS, PAEK, PBT, PP, PE, SC PI, and SC Polyamide), solvent, and the ceramic (AlOand/or ZrO), to dissolve the semi-crystalline polymer in the solvent; agitating the superheated mixture while substantially maintaining the mixture at an elevated temperature and pressure; and cooling the mixture to cause the semi-crystalline polymer to precipitate on the particles of the ceramic and thereby form a plurality of the present semi-crystalline polymer-ceramic core-shell particles. Methods of molding a part comprise subjecting a powder of the present semi-crystalline polymer-ceramic core-shell particles that substantially fills a mold to a first pressure while the powder is at or above a first temperature above a melting temperature (T) of the semi-crystalline polymers.