Effect of chemical treatment on mechanical and physical properties of non-woven kenaf fibre mat reinforced polypropylene composites

Kenaf fibre mat (KFM) reinforced polypropylene (PP) biocomposites have been prepared using sandwich structure and hot press moulding technique. To enhance the interfacial bonding between PP and kenaf fibre, KFM was chemically treated with four different chemicals which are 5% hydrogen peroxide, 5% alkaline (sodium hydroxide), 2% silane and 5% maleated polypropylene (MAPP). Fourier transform infrared (FTIR) was used to characterize the chemical constituents in both treated and untreated kenaf fibres. Universal tensile machine (UTM) was used to determine mechanical properties (tensile and flexural strength, tensile and flexural modulus and elongation at break) of both treated and untreated KFM biocomposites. Water absorption test was also conducted in order to evaluate its water resistance performance. The result shows that, peroxide treatment demonstrated the highest performance in mechanical and water absorption properties compared to others chemical treatment. SEM morphological studies proved that almost all treated KFM showing good fibre-matrix interfacial adhesion which less fibre pull out, void and small interface gap. Thus, the chemical treatment on KFM improved fibre-matrix adhesion, which also contributed to the enhancement of mechanical properties and physical properties compared to untreated KFM.