Abiotic an biotic degradation of reactive blends of polylactic acid - thermoplastic cassava starch reinforced with graphene nanoplatelets

Abstract

Biofilms of PLA, thermoplastic cassava starch (TPCS), and graphene nanoplatelets (GNP) were evaluated for abiotic and biotic degradation under simulated composting conditions at ~58 °C, ~50% of relative humidity (RH) and 120 days in compost. The evolved CO2, mineralization, and molecular number (Mn) were measured. A reduction of Mn was observed for PLA, indicating abiotic degradation. A priming effect was observed for the physical blend (PLA-TPCS), associated with the overproduction of CO2. A significant biodegradation rate was observed for TPCS phase. GNP at 1% produced a reduction in the lag phase of PLA and PLA-g-TPCS (reactive blend).