Patent ID: 8178643

Claim:
A molded polymeric structural member comprising: a single piece of polyurethane elastomer having a surface region and a core region, the surface region having a hardness that is less than a hardness of the core region, wherein the polyurethane elastomer is shaped and dimensioned as a building structure and is capable of being used as a load bearing member, wherein the polyurethane elastomer is formed from a combination of a polyisocyanate component and an isocyanate-reactive component, wherein the polyisocyanate component comprises at least one polymeric diisocyanate, and wherein the isocyanate-reactive component comprises between about 25% and about 35% of a first alkoxylated glycerol, between about 15% and about 25% of a second alkoxylated glycerol, wherein the first and second alkoxylated glycerols are different, between about 5% and about 10% of an alkoxylated triethanolamine, between about 12% and about 22% of an alkoxylated ethylenediamine, between about 8% and about 15% of castor oil, between about 5% and about 10% of an alkoxylated sucrose/glycerin polyol, between about 5% and about 10% of an aromatic diamine, all in percent of the isocyanate-reactive component by weight.