REACTIVE PROCESSING OF POLYMER BLENDS - ANALYSIS OF THE CHANGE IN MORPHOLOGICAL AND INTERFACIAL PARAMETERS WITH PROCESSING

The change in morphology and interface quantities have been analyzed for an immiscible polymer blend during reactive processing. A model polymer/polymer combination, hydroxy-terminated poly(epsilon-caprolactone)/liquid rubber with alpha, omega-carboxy groups, was employed. The blend was subjected to light scattering measurements, ellipsometry, and gel permeation chromatography (GPC). Size reduction of the dispersed phase during processing was followed by a systematic decrease in the correlation distance xi and an increase in the specific interfacial area Ssp, both by the Debye-Bueche plot of light scattering profiles. Also observed was the time variation of the volume fraction of interface V(lambda) estimated as a product of the Ssp and the interfacial thickness by ellipsometry. The changes in xi, Ssp, and V(lambda) with processing were accelerated when a coupling agent, gamma-aminopropyltriethoxysilane (APS), was added. The amount of block copolymer formed in-situ in the APS-loaded system was estimated by GPC with RI and UV detectors. For the size reduction kinetics in both APS-loaded and -unloaded systems, Rittinger's law was found to be applicable.