Study on the Crystallization of Poly(ethylene terephthalate)/SiO2/TiO2 Hybrid Nanocomposites by Sol-Gel Method

Abstract

The hybrid PET/TiO₂/SiO₂ composites were synthesized via the sol-gel method. A polymerization process resulted in the formation of Si-O-Ti bonds in the poly(ethylene terephthalate) (PET) matrix, which was confirmed by the appearance of the small new peak at ca. 937 cm^-1 in the fourier transform infrared spectroscopy spectrograms. The SiO₂-TiO₂ components had a significant effect on the crystalline morphology of the PET in PET/TiO₂/SiO₂ composites by polarized light microscopy observations from 290-190 ºC at a cooling rate of 5 ºC/min. The differential scanning calorimeter results exhibited that the crystallization behaviour of the PET was also influenced strongly by the inorganic nanoparticles due to the formation of the Si-O-Ti bonds in the matrix of composites The X-ray diffraction results were in a good agreement with the polarized light microscopy and the differential scanning calorimeter results, which indicated that the SiO₂-TiO₂ content affected the perfect degree of the PET crystal.