DEVELOPMENT OF A SIMPLE EXPERIMENTAL-METHOD TO MEASURE INTERPHASE COMPOSITION PROFILES GENERATED BY DIFFUSION IN POLYMERS - FURTHER RESULTSAND COMPARISON WITH RAMAN-SPECTROSCOPY

Composition profiles generated by interdiffusion in the concentrated r egime between poly(phenylene oxide)-polystyrene (PPO-PS) blend pairs a re experimentally determined by two techniques. Three-point bending mo ment measurements over a convenient temperature range (DMA (dynamic me chanical analysis) method) are used to determine interphase compositio n profiles. Confocal micro-Raman spectroscopy is also used to measure local compositions along a direction which is perpendicular to the ori ginal interface. The study includes some limiting cases, to test accur acy, precision and flexibility of the ''DMA method''. Excellent agreem ent is found between results obtained by both independent methods.