Abstract: A polymer casting formulation for producing molded polymeric structural members comprises a liquid mixture that contains a polyisocyanate component comprising at least two polyisocyanates; and an isocyanate-reactive component comprising at least two isocyanate-reactive compounds, which formulation cures to form a polyurethane. Methods of using the casting formulation to produce molded polymer structural members and the structural members that are produced by such a method are also described.

Abstract: Disclosed are composite structures having the appearance of knotty wood and methods for making such composite structures. Also described is a skin sheet imitating a knotty wood appearance. The skin sheet may be applied to a supporting framework to make a composite door or other type of building structure having the rustic look of natural knotty wood.