Preparation and Damping Property of Polyurethane/vinyl Ester Resin IPNs and Gradient IPNs

A series of polyurethane/vinyl ester resin(PU/VER) simultaneous and gradient IPNs curing at room temperature are successfully synthesized by changing the component ratios of PU or VER in IPNs and casting the mixtures of different component ratios in a mold at various times. The dynamic mechanical analysis(DMA) detection results indicated that, the component ratios of IPNs have great effect to damping of simultaneous IPNs. The tandelta values of 70/30~90/10(wt.%) IPNs both are higher than 0.3 for a temperature range of nearly 80 degC. And the temperature ranges are further broadened by controlling the techniques of gradient IPNs by varying the time interval of coating and component sequence. The tandelta values of 70/30~80/20~90/10 gradient IPNs with 3.5h interval are higher than 0.3 for a temperature range of near 100 degC . This opens up broad possibilities for manufacture of promising noise and vibration damping materials by gradient techniques