Optical Microscopy as a Tool to Correlate Morphology and Thermal Properties of Extruded PET/PC Reactive Blends

摘要

Catalysed and uncatalysed reactive extruded poly(ethylene terephthalate)/poly(bisphenol-A carbonate) (PET/PC) blends phase structure at compositional range containing 0-100 wt% of both parent polymers were evaluated. Phase separation was supported by TG/DTG, DMA and DSC. The changes on Tg and Tm of the parent polymers were associated to the esterification and transesterification reactions inside the phases and into the interfacial region. According to optical observations, not yet published in this matter, the blend morphology was dictated, either composition or melt flow rate and in the whole composition range, a matrix-droplet morphology was noticed. PET was only able to be crystallized in blends in which it was the matrix. Mostly, the PET/PC blends revealed to be partially miscible systems in which the level of the transesterification/esterification reactions was driven by the kind of matrix. The latter showed great influence on the thermal properties.