Effects of Compatibilizers in Void Formation: Biaxially-Oriented Polyethylene Terephthalate/Polyphenylene Ether Blend Film

Abstract
A functionally effective compatibilizer for PET/PPE blends is highly necessary to fabricate white opaque polyester film having high reflectance through drawing process. In this study, the effects of three different compatibilizers (SAN-g-MAH, SMA-16 and polystyrene-g-oxazoline PS-g-OXA) on the morphological, thermal, mechanical, and rheological properties in the PET/PPE (70/30, wt%) blend system were investigated. For the morphological studies, upon the addition of 7 part(s) per hundreds by weight (phr) of PS-g-OXA, the smallest domain size was observed among the three types used as a compatibilizer. Similarly, for the mechanical and rheological studies, upon the addition of 7 phr of PS-g-OXA, the optimal properties among three different compatibilizers were demonstrated due to the increased tensile strength and complex viscosity. For the thermal study, when the amount of PS-g-OXA added as a compatibilizer exceeded the threshold of the blend system, the T-g of the polyphenylene ether (PPE) was exhausted. In the morphological studies, the compatibilization effect was observed in the surface roughness of the film after stretching. It was concluded that PS-g-OXA was the effective compatibilizer for improving the reflectivity to make white opaque polyester film in PET/PPE blend system. It was concluded that this was due to compatibilization effects. Based on the results, the changes in properties were observed for biaxially oriented polyethylene terephthalate (PET)/PPE (70:30, wt%) blend films.