XPS AND SIMS CHARACTERIZATION OF SEGMENTED POLYETHER POLYURETHANES CONTAINING 2 DIFFERENT SOFT SEGMENTS

Angle dependent X-ray photoelectron spectroscopy (XPS) and static seco ndary ion mass spectrometry (SSIMS) were used to study the surface com position of two polyether polyurethane block copolymers. Both were syn thesised with 2,4-toluene diisocyanate and ethylene diamine as the har d segment, but different soft-segment compositions were used. In one c ase, the soft segment was polytetramethylene oxide (PTMO) while, in th e other case, it was a mixture of PTMO and polyethyleneoxide (PEO). Th e selection of the two oligomers for the soft segments allowed for an investigation of the influence of an elastomer's polar character on th e nature of chemical groups detected at the surface. By following the Cls signal and the atomic concentration of nitrogen with respect to ta ke off angle, it was shown that the surface of the films were depleted in nitrogen containing hard The study also showed that the sample hav ing both PTMO and PEO soft segments displayed a tendency for the PTMO to segregate from the PEO and migrate to the top surface, resulting in a depletion of the top layer in PEO. Static SIMS of this sample confi rmed this observation. Canadian Crown Copyright (C) 1998 Published by Elsevier Science Ltd. All rights reserved.