ABSTRACT
This chapter provides an overview of polymer structure-property relationships, focusing on polyurethane elastomers. The microphase structure of polyurethanes contributes to their mechanical properties; the phase separated structure is believed to account for their good biocompatibility as well. Assessment of the permeability characteristics of a material is important for membrane applications of polyurethanes. The electrical properties of polyurethanes are important in certain medical applications, such as pacemaker lead insulation, where low electrical conductivity or high resistivity are required. The extraction of nonpolymers from a polymeric material, including oligomers and manufacturing and processing additives can have implications for the final physical and biological performance of a given material. Knowledge of the solubility characteristics of a polymer also is useful in the evaluation of polymeric biomaterials. Stress hysteresis of polyurethanes can limit the applications of polyurethanes. The tensile strength of a polyurethane is dependent on temperature.
