Implementing plant-derived isosorbide and isomannide as comonomers for polyester synthesis: Effects of crystallization properties on optical properties

This article describes the implementation of plant-derived isosorbide (IS) and isomannide (IM) in the copolymerization modification of poly(ethylene terephthalate). The effects of the two comonomers on the optical, crystallization, and thermal properties of the resulting copolyesters were studied using the following analytical methods: proton nuclear magnetic resonance; differential scanning calorimetry; X-ray diffraction; thermogravimetry; and ultraviolet-visible spectroscopy. As comonomers, IS and IM increased the transmittance and reduced the haze of the copolyesters. Moreover, while IM improved the optical properties more than did IS, both monomers improved the optical properties of the copolyesters by lowering its crystallization ability. After the copolymerization modification, the crystallization rate of the copolyesters was reduced, decreasing the crystallinity and crystal size and thereby reducing the light transmission interference. The comonomers also altered the light absorption properties of the copolyesters and conferred a substantial increase in the transmittance of near-infrared (NIR) wavelengths. These changes in optical properties exhibit the potential of these comonomers for applications in optical materials and NIR detectors. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45444.