XPS AND STATIC SIMS STUDIES OF COPOLY(ETHER ESTERS) CONTAINING MIXED POLYETHER SOFT BLOCKS

The surface compositions for a series of copoly(ether-esters) are determined from XPS and static SIMS measurements. The copolymers consist of a polybutylene terephthalate (PBT) hard block and a mixed soft block of two of the following polyethers-poly(propylene glycol) (PPG), poly(tetramethylene oxide (PTMO) and poly(ethylene oxide) (PEO). The surfaces of all the copolymers are enriched in the total polyether soft blocks. Quantification of XPS intensities shows the presence of both polyethers at the surface of these mixed soft-block copolymers, in relative amounts close to the bulk formulations. In the static SIMS measurements, direct observation of characteristic fragment ions related to the specific polyethers confirms their presence and relative abundance in the surface.