Investigation of the Durability of Sisal Fiber/PLA Biocomposite through Evaluation of Biodegradability by Means of Microbial Growth

The aim of this work was to investigate the microbial biodegradation of 3-(trimethoxysilyl) propyl methacrylate (TPM) modified (silanized) sisal fibres/PLA biocomposites by Aspergillus niger . The modification of the sisal fibres performed excellently, improving hydrophobicity as well as mechanical properties. Compared to the unmodified sisal/PLA biocomposite, it produced superior interfacial adhesion between the fibres and the PLA matrix. In addition, silanization also increased the crystal size and crystallinity in the biocomposite, which decreased thermal decomposition to an observed maximal activation energy of 213 kJ/mol. This indicated the stability of silanized sisal biocomposite in resisting degradation. After the microbial growth test, despite the molecular weight of all biocomposites declining due to biodegradation, the silanized sisal PLA still possessed better properties than the unmodified biocomposite, particularly storage modulus, molecular weight and hydrophobicity, which reflected the inhibition of enzymatic degradation. Furthermore, the evidence of less erosion and fewer fungal hyphae on the surface of the modified biocomposite, was authentic confirmation of the inherent antimicrobial behavior of the silanized sisal /PLA biocomposite.