Effect of aluminum trihydroxide on flame retardancy and dynamic mechanical and tensile properties of kenaf/poly(lactic acid) green composites

In this work, the effect of aluminum trihydroxide (ATH) on the flame retardancy and dynamic mechanical and tensile properties of kenaf/poly(lactic acid) green composites was explored. Prior to composite fabrication, poly(lactic acid) (PLA) pellets filled with ATH powder at different loadings (0, 10, 20, 30, and 50 wt.%) were processed by using a twin-screw extrusion technique. The green composites were fabricated using the pellets and chopped kenaf fibers by a compression molding method. The kenaf fibers were used as primary reinforcement, and the contents were fixed to 40 wt.% of the total, and the average fiber length was 3mm long. It was noticeable that the flame retardancy of kenaf/PLA green composite with ATH was improved by 66%, and the storage modulus and tensile modulus were enhanced by 136 and 59%, respectively, compared with the kenaf/PLA counterpart without ATH. It was concluded that the ATH incorporated into PLA by extrusion technique played a significant role not only as flame-retardant but also as secondary reinforcement of kenaf/PLA green composites.