Surface analysis of biomedical materials is necessary for determination of surface structure/biological property relationships. Previous studies [3,6] have demonstrated the applicability of Angle Resolved X-Ray Photoelectron Spectroscopy (ARXPS or ARESCA) and Fourier Transform Infrared Spectroscopy (FT-IR) with Attenuated Total Reflectance (ATR) sampling. Using these surface sensitive techniques on currently marketed segmented polyurethanes (SPU) (Biomer TMand Cardiothane-51TM), we have investigated chemical and morpholgical differences between polymeric mixtures cast from solvents of varying polarity. These materials are used because of their resistance to degradation and hydrolysis.
Results will show: (1) Selective casting of different constituents of the mixture as monitored by FT-IR, where polymers can be represented as opposed to block copolymers; (2) Correlation between the Hildebrand solubility parameter of the casting solvent and the portion of the polymer selectively cast; (3) Models of solution cast polymers will be presented including (concentration gradient) of the constituents; (4) SEM micrographs will provide information on domain size and the formation of these solution cast films; (5) Depths and concentration gradients will be estimated by comparing results from AHXPS and variable angle FT-IR/ATR.