Crystallization Behavior of Poly(lactic acid)/Titanium Dioxide Nanocomposites

Abstract

In this study, a poly(lactic acid) (PLA) with various titanium dioxide (TiO2) nanoparticles loading were prepared by a manual laboratory mixing method. The effect of TiO2 nanoparticles on the non-isothermal and the isothermal crystallization behavior of PLA were investigated by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The presence of TiO2 nanoparticles decreased the spherulite growth rate of PLA, whereas it initiated faster crystallization through the heterogeneous nucleation process as observed by optical microscopy. The results of DSC analyses confirmed that the TiO2 nanoparticles act as an efficient nucleating agent for PLA crystallization. The cold crystallization temperature and crystallization half-time of PLA decreased, while degree of crystallinity of PLA increased in relation to increases of TiO2 nanoparticles.