Biodegradation Assessment of Poly (Lactic Acid) Filled with Functionalized Titania Nanoparticles (PLA/TiO 2 ) under Compost Conditions

Abstract

This paper presents a biodegradation study conducted for 90 days under standardized controlled composting conditions of poly (lactic acid) (PLA) filled with functionalized anatase-titania nanofiller (PLA/TiO 2 nanocomposites). The surface morphology, thermal properties, percentage of biodegradation, and molecular weight changes at different incubation times were evaluated via visual inspection, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC) by taking degraded samples from compost at the end of target biodegradation time interval. The rapid increase of crystallinity indicated that the PLA and PLA/TiO 2 nanocomposites had heterogeneous degradation mechanisms under controlled composting conditions. The biodegradation rate of PLA/TiO 2 nanocomposites was higher than that of pure PLA because water molecules easily penetrated the nanocomposites. The dispersion of the nanoparticles in the PLA/TiO 2 nanocomposites affected the biodegradation rate of PLA. Moreover, the biodegradation of PLA could be controlled by adding an amount of dispersed TiO 2 nanofillers under controlled composting conditions.