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. ...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.展开更多
High-pressure crystallization behavior of poly(ethylene terephthalate)(PET)/biphenol-A polycarbonate(PC) blends were investigated by scanning electron microscopy(SEM) and atomic force microscopy(AFM).Two novel spherul...High-pressure crystallization behavior of poly(ethylene terephthalate)(PET)/biphenol-A polycarbonate(PC) blends were investigated by scanning electron microscopy(SEM) and atomic force microscopy(AFM).Two novel spherulitic structures,i.e.bamboo-shoot-like spherulite and brain-like spherulite,were observed in the polyester extended-chain crystals.The extended-chain lamellar crystal may be the substructure of these spherulites.This morphology,which is quite different from that of usual spherulite and extended-chain crystal,may promote the understanding of formation process and mechanism for both polymer spherulites and extended-chain crystals.展开更多
文摘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.
文摘High-pressure crystallization behavior of poly(ethylene terephthalate)(PET)/biphenol-A polycarbonate(PC) blends were investigated by scanning electron microscopy(SEM) and atomic force microscopy(AFM).Two novel spherulitic structures,i.e.bamboo-shoot-like spherulite and brain-like spherulite,were observed in the polyester extended-chain crystals.The extended-chain lamellar crystal may be the substructure of these spherulites.This morphology,which is quite different from that of usual spherulite and extended-chain crystal,may promote the understanding of formation process and mechanism for both polymer spherulites and extended-chain crystals.
