Preparation and characterization of poly(lactic acid)-grafted TiO2 nanoparticles with improved dispersions

Poly(lactic acid) (PLA)-grafted TiO2 particles were prepared by in situ melt polycondensation of lactic acid onto the surface of TiO2 nanoparticles. The resulting products were characterized by FTIR, XPS, TG-FTIR, XRD analysis and electron microscopy observation so as to have a better understanding of bonding between the graft polymer and nanoparticles. New characteristic peaks of Ti-carboxylic coordination bond, the changes in the relative intensities of the infrared absorption bands of graft polymer and the two decomposition stage of PLA-grafted TiO2 confirmed that PLA was grafted on the surface of TiO2 nanoparticles. By attachment of PLA, the PLA-grafted TiO2 samples exhibited much better dispersion and a slightly larger particle size than bare TiO2 particles. PLA-grafted TiO2 nanoparticles will find wide applications in biomedical and eco-friendly materials, especially as fillers in PLA matrix.