Preparation and characterization of PLA/ZnS nanocomposites via an in situ solvothermal process

Abstract

Homogenous poly(lactic acid) (PLA)/zinc sulfide (ZnS) nanocomposites were successfully prepared via a solvothermal method with lactide, zinc acetate, and carbon disulfide as precursors. In this process, the cationic ring-opening polymerization of lactide and the formation of ZnS nanoparticles were taken place simultaneously, and PLA/ZnS nanocomposites were obtained in situ way. The effect of reaction temperature, time, and zinc acetate content on the molecular weight of PLA was discussed. Ubbelohde viscometer, TEM, UV-vis, TGA, and fluorophotometer were used to characterize the obtained nanocomposites. It was found that homogonous PLA/ZnS nanocomposites could be obtained at 160°C for 8 h with toluene as reaction medium. Comparing to pure PLA, the molecular weight of PLA in the obtained nanocomposites increased, and ZnS nanoparticles with the size about 10 nm in diameter were dispersed well in PLA matrix without any dispersan. The PLA/ZnS nanocomposites have ultraviolet resistant. © 2012 Wiley Periodicals, Inc.