COMPATIBILITY OF BLENDS OF POLY(ETHYLENE-TEREPHTHALATE) WITH THE IONOMER OF ETHYLENE METHACRYLIC-ACID COPOLYMER

The compatibility behaviour of melt-mixed blends of poly(ethylene terephthalate) (PET) with the sodium ionomer of poly(ethylene-co-methacrylic acid) were investigated in the complete composition range. The techniques used were dynamic mechanical analysis (DMA), DSC, tensile properties, optical and electronic microscopy. DMA indicated a non-miscible blend except at the high ionomer contents. Tensile properties were good indications of mechanical compatibility resulting from good component adhesion. Considerable interaction was also revealed from the T(m) depression of the two crystalline blend components and the composition dependence of blend crystallinity. Morphology examination with SEM corroborated these findings. On the basis of preliminary tensile testing, it is also demonstrated that the ionomer may be used as an effective compatibilizer for PET/LLDPE.