Preparation and crystallization of poly(ethylene terephthalate)/SiO2 nanocomposites by in-situ polymerization

Poly(ethylene terephthalate) (PET)/SiO2 nanocomposites were prepared by in situ polymerization. The dispersion and crystallization behaviors of PET/SiO2 nanocomposites were characterized by means of transmission electron microscope (TEM), differential scanning calorimeter (DSC), and polarizing light microscope (PLM). TEM measurements show that SiO2 nanoparticles were well dispersed in the PET matrix at a size of 10–20 nm. The results of DSC and PLM, such as melt‐crystalline temperature, half‐time of crystallization and crystallization kinetic constant, suggest that SiO2 nanoparticles exhibited strong nucleating effects. It was found that SiO2 nanoparticles could effectively promote the nucleation and crystallization of PET, which may be due to reducing the specific surface free energy for nuclei formation during crystallization and consequently increase the crystallization rate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 655–662, 2006