Effect of in situ reactive interfacial compatibilization on structure and properties of polylactide/sisal fiber biocomposites

The interfacial property is of great importance for polymer composites materials. In this study, polylactide (PLA) and sisal fibers (SF) were melt‐blended to fabricate bio‐based composites via in situ reactive interfacial compatibilization with addition of triglycidyl isocyanurate (TGIC). The interfacial adhesion between PLA matrix and sisal fibers was improved, which was confirmed by scanning electron microscope characterization. TGIC played a hinge‐like role between fibers and matrix, which bonded the PLA molecular chain to the fiber surface. FTIR analysis after Soxhlet extraction demonstrated the bonding of PLA molecular chain to the fiber surface. At the same time, the interfacial reaction and microstructures of composites were further investigated by thermal and rheological analyses. Differential scanning calorimetry and dynamic rheological measurement indicated that the mobility of the PLA molecular chain in composites was restricted because of introduction of TGIC, which also reflecting the improved interfacial interaction between sisal fibers and PLA matrix. The tensile properties of composites were improved because of improved interfacial adhesion between sisal fibers and PLA matrix. POLYM. COMPOS., 39:E174–E187, 2018. © 2017 Society of Plastics Engineers