End-of-life evaluation and biodegradation of Poly(lactic acid) (PLA)/Polycaprolactone (PCL)/Microcrystalline cellulose (MCC) polyblends under composting conditions

Abstract

The present study evaluates biodegradation of the polyblends of poly(lactic acid) (PLA), polycaprolactone (PCL) and microcrystalline cellulose (MCC) in different compositions and comparison of the properties of those blends with that of neat PLA and neat PCL. The samples were melt extruded and blended to evaluate the environmental fate of the polyblends under simulated composting conditions following the standard ASTM International D5338-15 protocol. It was seen that blends with a higher concentration of PCL and MCC in the PLA matrix showed higher carbon mineralization percentage in comparison to the blends having low PCL and MCC components. Molecular weight analysis of the samples showed a decrease in their weight due to chain scission mechanism leading to the formation of intermediates. Analytical techniques revealed the formation of microbial biofilms on the blended biopolymeric surfaces. Field emission scanning electron microscopy showed the formation of fibril-like structures by PLA, and the formation of rough patches on the PCL surface re-confirmed biodegradation of the samples. This work fuels interest in the material characterization of PLA/PCL/MCC based polyblends and helps in tuning the biodegradability of the studied samples according to the demands.