THE EFFECTS OF TRANSESTERIFICATION ON THE PROPERTIES OF POLY(ETHYLENE 2,6-NAPHTHALENE DICARBOXYLATE) /POLY(ETHYLENE TEREPHTHALATE) BLEND FILMS

摘要

The surface properties of poly (ethylene 2,6-naphthalene dicarboxylate) / poly(ethylene terephthalate) [PEN/PET] blend films were studied. Blending of PET with PEN results in transesterification reactions between the two polymers. It was found that transesterifiation led to not only inducing miscibility of the two polymers but also decreasing crystallinity of blend films. The effect of transesterification on the crystallinity is more conspicuous in films prepared with low cooling rate and without inhibitors. The linear relationship between crystallinity and surface roughness was found in films with either low crystallinity or low transesterification. With increasing the level of transesterification, the roughness of films becomes uniform. The crystallite size controlled by cooling conditions and inhibitors was also influenced the surface roughness. Inorganic fillers for PET films such as CaCO_3 and SiO_2 were contributed to decreasing transesterification as well as increasing crystallinity, however, it seems that the surface roughness of filled PEN/PET blend films is primarily associated with the existence of the filler itself.