Flame Retardancy and Non-isothermal Crystallization Behaviour of PET/TiO^sub 2^ Nanocomposites

Titanium dioxide particles (TiO^sub 2^) have been melt-compounded with poly(ethylene terephthalate) (PET) by using a twin-screw extruder to prepare PET/TiO^sub 2^ nanocomposites. The flame retardancy and non-isothermal crystallization behaviour of PET and PET/TiO^sub 2^ nanocomposites have been studied using several techniques. The effects of TiO^sub 2^ on the combustion behaviour of PET/TiO^sub 2^ nanocomposites were analyzed by CONE and SEM. The results showed that the HRR, THR and TSR of nanocomposites was reduced significantly. The char residues were examined using scanning electron microscopy, indicating that TiO^sub 2^ addition produced consistent and compact char crusts. The non-isothermal crystallization behaviour of PET and PET/TiO^sub 2^ were investigated by differential scanning calorimetry (DSC). Meanwhile, the kinetics of non-isothermal crystallization was analyzed by the Mo Zhishen method. Both results showed that the TiO^sub 2^ in PET acted as an effective nucleation agent. Not only was the crystallization rate of composites obtained higher than that of the neat PET, but also the crystallization time of the composites obtained was shorter than that of the neat PET. The presence of TiO^sub 2^ changed the mechanism of the nucleation and accelerated the rate of PET crystallization. [PUBLICATION ABSTRACT]