THE EFFECTIVENESS OF SPETG AS A COMPATIBILIZER FOR PC/PETG BLENDS

摘要

The melt-mixed blends of an amorphous copolyester, poly(ethylene-co-cyclohexane 1,4-dimethanol terephthalate) (PETG) and the sulfonated analog of the copolyester (sPETG), with bisphenol-A polycarbonate (PC) were investigated over the entire composition range. Dynamic mechanical analysis (DMA) for the PC/PETG blends showed two, α-relaxations, which coincided with the glass-transition temperatures of the two respective homopolymers. In contrast, the PC/sPETG blends displayed two α-relaxations but with a shift of the PC α-relaxation to lower temperatures. Unlike the PC/PETG blends, the tensile strain at break and yield stress for the PC/sPETG blends follows closely to a linear composition dependence due to greater interaction between the blend components. Analysis of the FT-IR spectra for the PC/sPETG blends indicates an interaction between the sulfonate group of sPETG and the carbonyl group on the PC backbone.