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.