In situ synthesis of poly(ethylene terephthalate-co-isophthalate)–SiO2 nanocomposites and their optical properties

In this paper, poly(ethylene terephthalate- co -isophthalate) was prepared and a series of PETI/SiO 2 nanocomposites with different amounts of silica nanoparticles was synthesized by in situ polymerization. Optical properties of the resultant nanocomposites were investigated by WGW photoelectric haze meter and UV–Vis-NIR spectrophotometer. Chemical structure and its influence on spherulite size of nano-SiO 2 were characterized by Fourier transformed infrared spectra and polarized optical microscopy, respectively. The differential scanning calorimetry results reveal that the addition of nano-SiO 2 has an impact on the thermal performance of the nanocomposite. Different proportions of SiO 2 were compared and the degree of crystallinity was found to have influence on optical properties of as-prepared nanocomposites. In addition, the results indicate that the low loading levels of SiO 2 can improve the optical properties of the composite and an optimum content was selected. Possible reasons for this enhanced role might be the different combination structure of the nanocomposites when the amount of SiO 2 varied.