The aim of this paper is to demonstrate a new technology to fabricate controlled and uniformly distributed porous ceramic structures from the blends of polyolefin and preceramic polymers by compounding and subsequent pyrolysis. As examples, porous silicon oxycarbide ceramics with either fully open-celled or major close-celled structures, with cell porosities ranging from 20.5% to 79.8%, cell densities higher than 108 cells/cm3 and cell diameters smaller than 50 μm, were made from lowdensity polyethylene (LDPE) and polysiloxane blends. The LDPE powders and polysiloxane were directly compounded using a counter-rotated twin-screw extruder with a filamentary die, and then the specimens obtained were transformed into porous silicon oxycarbide ceramics by controlled pyrolysis.

Keywords: Porous ceramics, Silicon oxycarbide, Polysiloxane, Extrusion.