Biodegradation of PBAT-Silane Functionalized Nanocellulose Composite Films Under Industrial Composting Condition

Abstract

Efforts to develop biodegradable plastics are ongoing in response to growing environmental concerns. However, the post-use fate of these materials is not always well understood. This study aimed to evaluate the biodegradation behavior of poly(butylene adipate-co-terephthalate) (PBAT) and its composites. The aim of this study was to determine the biodegradation of poly(butylene adipate-co-terephthalate) (PBAT) and its composites. The nanocomposites were produced by melt blending PBAT with either 5 wt% unmodified cellulose nanocrystals (PBAT-CNC) or 5 wt% phenyl silane modified cellulose nanocrystals (PBAT-CNCPhS). The aerobic biodegradation of the composite films was studied for their physical disintegration behavior under simulated industrial composting conditions (58°C ± 2°C) for 120 days. Additionally, respirometric biodegradation tests were separately carried out to assess CO2 evolution and the extent of mineralization under the identical conditions. Surface morphology and thermal degradation of representative partially degraded samples were also analyzed. The effect of unmodified and silane modified cellulose nanocrystals (CNCs) on the biodegradation of the composites was evaluated. Both PBAT-CNC and PBAT-CNCPhS composite films exhibited faster fragmentation and mass loss compared to that of PBAT. The hydrolysis of the nanocomposite was moderately restricted by phenyl silane modified CNCs, but this effect was only observed for the first 28 days. The composites demonstrated the following order in terms of fragmentation and CO2 evolution: PBAT-CNC > PBAT-CNCPhS > PBAT. The composite materials produced using silane-modified CNCs are suitable for use as biodegradable plastics.