Transparent Polyurethane Elastomers

Abstract

Interest in transparent polyurethane elastomers (PU's) both as thermoset and thermoplastic elastomers has increased over recent years due, in part, to their high impact strength and energy absorption properties which ensure failures to be ductile in nature. This is attributable to the combination of high tensile strength and elongation at break (several lOO's percent) possessed by PU's. Similar materials such as the polycarbonates and polymethylmethacrylates possess much lower elongation at break values and hence whilst possessing some ductility their overall energy absorption properties are inferior to those of PU's. This has resulted in transparent PU's being used as interlayer materials for automobile and aeroplane laminated windscreens, energy absorbing protective outer or inner layers for windscreens of high speed vehicles, shatterproof coatings for glass containers, and for many medical appliances.