Chemical and structural modification of polyurethaneureas by surface-modifying macromolecules

grantor: University of TorontoSurface modifying macromolecules (SMMs) have been developed which migrate to the surface of polyurethaneureas and inhibit hydrolytic degradation. The physical and chemical properties of the pure SMMs were related to chemical interactions at the surface of the blended polymers. These interactions were used to explain differences in the inhibition of oxidative and hydrolytic biodegradation. The stability of two of the SMMs at the blend surface was assessed with the goal of identifying SMM-related degradation products. SMMs based on several chemistries were synthesized and incorporated into polyester and polyether polyurethaneureas in a 4 wt% concentration. Surface modification was effected with minimal change to the bulk polymer structure. The ability of the SMMs to reduce hydrolysis was related to hydrogen bonding interactions with the base polymer and the response of the surface to hydration. The SMMs were stable at the surface and did not release detectable levels of SMM-related degradation products.M.A.Sc