SAXS ANALYSIS OF A LINEAR POLYESTER AND A LINEAR POLYETHER URETHANE - INTERFACIAL THICKNESS DETERMINATION.

In the reported experiments, a small-angle x-ray scattering (SAXS) investigation of two linear segmented polyurethanes was carried out to learn about the respective domain structure (morphology). Both urethanes had a hard segment of methylene-bis(4)phenyl isocyanate (MDI) and butanediol. Using an automated Kratky camera, SAXS scans were made. By detailed analysis (using the computer program of Vonk) the average interfacial thickness E of the domains was determined by two approaches. The value of E for the polyester was 10-12 A, while it was 5-7 A for the polyether. Other aspects of the analysis provided further information on the morphological structure. Some cautionary comments are provided on the use of quantitative SAXS data obtained from these or similar systems.