Silicon carbide-modified fluoropolymer powders

摘要

A method for preparing a modified fluoropolymer powder comprises the steps of forming a suspension of solid fluoropolymer particles together with silicon carbide (SiC) particles as a modifier in an aqueous carrier, freezing the aqueous suspension, and subjecting the frozen suspension to sublimation to produce dry powder of a modified fluoropolymer. Typically, the fluoropolymer is perfluoromethyl vinyl ether (MFA) having a particle size of 30-350 nm. The silicon carbide may have a particle size of up to 50 microns and may comprise up to 2 wt.% of a MFA/SiC mixture. The aqueous suspension is preferably frozen at -60{C to -20{C and may be frozen in trays. The modified fluoropolymer particles may also be subjected to milling and/or irradiation.