Mechanical, damping, and thermal properties of calcium sulfate whisker-filled castor oil-based polyurethane/epoxy IPN composites

A series of calcium sulfate whiskers (CSW)-filled, castor oil-based polyurethane/epoxy resin graft interpenetrating polymer network (IPN) composites were prepared. The tensile and impact strengths, fractured surfaces, damping properties, and thermal stability of the IPN composites were studied systematically in terms of composition. Results revealed that the addition of CSW can significantly improve the tensile strength though the impact strength was impaired. The damping properties were the best when the CSW content was 3%. The thermal decomposition temperature was also improved by the incorporation of CSW. It is expected that the CSW-filled IPN composites may be used as structural damping materials.