Miscibility of a PET/PEN blend studied by dynamic mechanical analysis

In this work, dynamic mechanical analysis (DMA) was used to investigate the solid state rheological properties of amorphous poly(ethylene terephthalate) (PET), poly(ethylene 2,6-dicarboxylate) (PEN) and the corresponding blend (1:1 by wt). The DMA results obtained with the pure materials were used to predict the expected viscoelastic behaviour of the blend assuming a complete phase separation. The modelling showed more separated tan … peaks, as compared to those experimentally found in the real PET/PEN blend. These results suggested that some degree of compatibilization is present in the blend. This effect was attributed to the fine homogenisation of the phases during the preparation of the blend, as well as to the occurrence of interchange chemical reactions (transesterification) taking place between the PET and PEN components.(undefined