Damping materials based on polyurethane/ polyacrylate IPNs : dynamic mechanical spectroscopy, mechanical properties and multiphase morphology

Four kinds of polyurethane/polyacrylate interpenetrating polymer networks (crosslinked polyacrylate semi-IPNs, crosslinked polyurethane semi-IPNs, all-IPNs and all-IPNs with opposite charge groups) were synthesized by a simultaneous polymerization process. Their damping properties, mechanical properties and multiphase morphology were investigated by automatic torsional braid analysis, an Instron tester, small-angle X-ray scattering (SAXS) and tranmission electron microscopy (TEM). The results show that the attraction between positively charged groups and negatively charged groups improved the miscibility of the two components. When the weight ratio of polyurethane/polyacrylate was 1:2, the resulting IPN materials possessed better damping and mechanical properties, and the specific surface area reached a maximum. © 1999 Society of Chemical Industry