PREPARATION AND PROPERTIES OF PHENYLENE OXIDE-ARYL ETHER SULFONE BLOCK-COPOLYMERS AND THEIR BLENDS

We have prepared triblock copolymers of poly(phenylene oxide) (PPO) an d polysulphone (PSF) of the form PPO-PSF-PPO in order to assess their intrinsic mechanical properties and their potential as interfacial com patibilizers in polystyrene/PSF blends. For sufficiently long polysulp hone block lengths, we observed microphase separation both in the trib lock copolymers and in their blends with polystyrene. The triblock pol ymers, nevertheless, showed very similar microdeformation behavior to the PPO homopolymer, suggesting the phase separation to play a minor r ole. On the other hand, the compatibility of the poly(phenylene oxide) blocks and polystyrene ensured a high degree of interphase adhesion i n blends containing both polystyrene and free PSF, even for relatively high homopolymer molecular weights. (C) 1996 John Wiley & Sons, Inc.