The Effect of Alkaline Treatment on Mechanical Properties of Polylactic Acid Reinforced with Kenaf Fiber Mat Biocomposite

Abstract Kenaf fiber mat (KFM) reinforced polylactic acid (PLA) biocomposite have been developed by using film stacking and compression molding. In order to achieve the composite with good mechanical properties, the effect of processing parameters such as processing temperature and heating time on mechanical properties of PLA was studied. The optimum values of processing temperature and heating time on mechanical properties of PLA that were obtained were then being used to produce PLA/KFM biocomposite. PLA and kenaf fiber has distinct properties as natural fiber is hydrophilic whereas the polymer matrix is hydrophobic. In order to improve the fiber matrix adhesion, the KFM was chemically treated at different concentrations of NaOH for 3 hours at room temperature. Mechanical properties such as tensile and flexural strength, tensile and flexural modulus and elongation at break of untreated and alkali-treated PLA/KFM biocomposite were studied and compared. The obtained results showed that the alkali treatment have impact on the mechanical properties of PLA/KFM biocomposite. The study has demonstrated that the optimum alkali concentration was 4% NaOH concentration.