Synthesis and characterization of nanosized polylactic acid/TiO2 particle brushes by azeotropic dehydration polycondensation of lactic acid

A method for the synthesis of particle brushes by grafting polylactic acid onto TiO2 nanoparticle is reported. The efficiency of grafting was enhanced by combining azeotropic separation of water with polycondensation in a single pot. PLA/TiO2 brushes synthesized with different ratio of lactic acid and TiO2 were characterized by various techniques such as FT-IR, XRD, TEM, XPS, H-1 and C-13 NMR. TEM analysis indicates that the sizes of TiO2 nanoparticles are between 2 and 8 nm. DLS was used to determine overall size of particle brush and average size varied between 59.68-65.83 nm. Zeta potential measurement indicated high stability of water dispersed particles brushes with measured values of -30.1 to -37.1 mV for brushes prepared with PLA/TiO2 ratio of 50: 1 and 20: 1 respectively. The DSC and TGA analysis showed that PLA/TiO2 nanocomposites have good thermal stability.