Biodegradable kinetics and behavior of bio-based polyblends under simulated aerobic composting conditions

The current study evaluates aerobic biodegradation of melt extruded poly(lactic acid) PLA based blends under composting conditions. Samples of neat PLA (NPLA) and bio-based polyblend composites of PLA/LLDPE (linear low-density polyethylene) having different concentration of MCC (microcrystalline cellulose crystal) were analyzed to understand the biodegradation behavior of these blends under simulated composting conditions. Biodegradation kinetics revealed that higher content of MCC and PLA accelerated the biodegradation process of the polymeric blends. Increase in the spherulite growth size and decrease in the spherulite density of the biodegraded samples confirmed the decline in amorphous portion of the test samples due to microbial assimilation, leaving behind the crystalline portion. Surface morphological analysis revealed that the samples of PLA/LLDPE/ MCC blends underwent surface erosion prior to bulk biodegradation (50-80%) until the 90th day and the PLA formed fibril-like structures after degradation. This study would help in the design and preparation of biodegradable bio-based commercial blends in the future.