INTERPENETRATING POLYMER NETWORKS OF POLYURETHANE CROSS-LINKED EPOXY AND POLYURETHANES

Interpenetrating polymer networks (IPNs) were prepared from polyuretha ne (PU) crosslinked epoxy and polyurethanes based on the mixture of po lydiol and polytriol by the one-shot method. The mechanical properties , dynamic mechanical properties, morphology and damping behaviour were investigated. The results show that the damping ability and mechanica l strength are enhanced through the introduction of PU cross-linked ep oxy into the PU matrix to form the IPN structure. As the epoxy content increases, the tensile strength of the two types of the IPNs decrease in low composition, then increase in high composition. The damping pr operties of the PU (polyether type) cross-linked epoxy/PU IPNs are muc h better than those of the PU (polyester type) cross-linked epoxy/PU I PNs, but the mechanical properties reveal an opposite tendency. The sa mple with 20 wt% epoxy content in the PU cross-linked epoxy/PU IPNs sh ows particle-matrix morphology and exhibits good damping properties.