Fabrication of Interconnected Porous Elastomers by a Microsphere‐Templating Process

Abstract

ABSTRACTIn this work, a solvent‐free microsphere‐templating process was developed to fabricate porous elastomers. The process starts with preparation of a porous wax template by thermal sintering at a temperature close to the wax melting temperature. Then, low‐viscosity monomers for elastomeric polyurethane were cast into the wax template. Finally, after casting and curing of the elastomer, the wax component was removed by mechanical forces (centrifuge or squeezing) to produce a porous elastomer. With this process, polyurethane scaffolds with a co‐continuous porous structure were successfully prepared. The optimal sintering temperature for the wax template was attained about 4°C below the wax peak melting temperature, leading to a stable process for joining wax microspheres into a three‐dimensional porous template. Mechanistic approaches were found to be effective for extracting wax in the cast polyurethane; more than 90% of wax can be simply removed by mechanical squeezing above the wax melting temperature. After wax removal, the polyurethane demonstrated a morphology with micropores interconnected by microchannels, indicating the interconnectivity of the porous structure. Tensile tests showed that the resulting porous material is highly deformable and elastic, exhibiting typical properties of polyurethane elastomers. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 2013, 32, 21330; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21330