Sustainable hemp fiber reinforced polylactic acid/poly(butylene succinate) biocomposites: Assessing the effectiveness of MAH-g-PLA as a compatibilizer

Abstract

The unsustainability of petroleum resources and the growing issue of plastic pollution necessitate the development of sustainable biocomposites as alternatives to synthetic materials. On this basis, a blend of biosourced poly(lactic acid) (PLA)/poly(butylene succinate) was reinforced with hemp fibers (HF) in various amounts (5–10–20-30 wt%). In order to facilitate the interaction between PLA/PBS and HFs, maleic anhydride grafted PLA (MAH-g-PLA) was added to the biocomposite containing 20 wt% HF at various ratios to produce compatibilized biocomposites. All samples were processed by melt blending and injection molding and characterized. The Fourier transform infrared spectroscopy was used to determine whether the MAH group interacts with -OH groups through reactive processes. However, the compatibility is deemed insufficient due to the low reactive compatibility and inadequacy of the PBS and HF end groups, which failed to enhance the tensile strength property of composites. Differential scanning calorimetry demonstrated that the crystallinity of the matrix, which decreased with the addition of HF, increased markedly with the incorporation of the compatibilizer. The poor interfacial adhesion observed between PLA/PBS and HF in scanning electron microscope images resulted in a reduction in tensile strength while the modulus increased. The compatibilizer did not lead to a considerable enhancement in tensile strength, but the modulus increased considerably. HF and MAH-g-PLA slowed the thermal degradation of the matrix and improved its thermomechanical properties. However, it can be concluded that MAH-g-PLA is not a sufficiently effective compatibilizer for this biocomposite.