The effectiveness of bentonite and esterified plant fibers on the biodegradability of 24 polypropylene biocomposites

This study aims to evaluate the biodegradability of 24 bio-composites synthesized from polypropylene and esterified plant fibers, with bentonite serving as a filler. The biodegradation process was conducted using Aspergillus niger. The study utilized standard laboratory equipment and the melt flow indexer. After three months of biodegradation, all biocomposites under investigation showed a significant loss in their weights. This is a logical observation because Aspergillus niger consumed parts of biocomposites as food during the biodegradation. The study also evaluated properties including density, melting point, melt flow rate (MFR), melt viscosity, molecular weight, and water absorption capacity. Densities, melting range temperature, and molecular weights were decreased (decreasing in molecular weights). The values of biodegraded composites after the biodegradation process for three months are in good agreement with the fact that the molecular chain breaks and the chain length shortens after any degradation process. Water absorption capacities were significantly increased (due to the holes resulting from the Aspergillus niger attack) for all biocomposites under study; this is considered very good evidence for biodegradation.