| Abstract: | Poly(ether urethane)s as biomaterials display certain favorable mechanical and biocompatibility properties. Earlier studies suggest that improved blood compatibility might be attained by introducing hydrocarbon groups at the surface. We synthesized and characterized a series of polyurethanes in which a N-2,3-dihydroxypropyl-N′-octadecyl urea chain extender (ODCE) was incorporated into the poly(tetramethylene glycol) (PTMO)/4,4′-methylenebis(phenylene isocyanate) (MDI) system. Molecular weights of the polymers varied between 40,000 and 250,000. An electron spectroscopy for chemical analysis (ESCA) study of the ODCE polyurethane surface revealed a substantially enhanced hydrocarbon concentration compared to a control PTMO/MDI/ethylene diamine (ED) polyurethane surface. Also, bulk composition analyses and ESCA data of the ODCE polymers indicated that the percentage of carbon was higher in the surface region than in the bulk. Thus, the ODCE polymer showed a marked increase in hard-segment concentration in the surface region compared to the bulk region and to the ED polymer. |
