Prof. Shahrom Mahmud
Universiti Sains, Malaysia
Research Area
Nanophysics, Semiconductor, High Voltage MOV, Optoelectronics, Nanoparticles, Biomaterials, Composites.
A.Prof. Siti Norasmah Surip
Universiti Teknologi MARA, Malaysia
Research Area
Nano Materials & Composites, Bio/Green Composites, Polymer/Rubber Toughened.
Title of Keynote Speech
Characterization of Bio-degradable natural fiber composites made from Kenaf fibers and polylactic acid (PLA).
Abstract
This study was conducted to produce green composites from natural sources and has the ability to self-degraded at the end of life due to environmental concern. Natural fibre (kenaf fibre) reinforced natural polymer, polylactic acid (PLA) was used for production of green composites. Kenaf bast and core fibre was separated and treated similarly to reinforce PLA. The effect of preparation condition such as acid hydrochloric concentration, extrusion rotation speed and amount of fibre loading was used to investigate composites properties. While the effect of natural weathering and landfill burial on composites properties was investigated for its degradation. Kenaf fibre was treated at 6% w/w NaOH followed by various HCl concentrations (0.5 M, 1.0 M, and 1.5 M). Fibres were then cryo-crushed to reduce size and compounded with PLA at various rotation speed (60, 70, and 80 rpm) and fibre loading (2, 4, and 6%) to determine the optimum parameter. Mechanical properties (flexural and impact), thermal properties (TGA and DSC), microscopic observation (SEM and TEM), Fourier Transform Infra-Red (FTIR), X-Ray Diffraction (XRD) were done for the investigation of the composites properties. Results reveal that treatment at 1.0 M HCl, with 60 rpm extrusion speed and 2% fibre loading has optimum properties for both Kenaf-bast-fibers composite (KBC) and Kenaf-core-fibers composite (KCC). Interestingly, KCC has comparable strength with KBC where statistical analysis shows no significant difference in the value of most mechanical properties. Although KCC present slightly lower thermal stability than KBC, temperature difference was in smaller range. It is proved that reinforcing ability of kenaf core fibre is as similar as kenaf bast fibre. In addition, reinforced composites (KBC and KCC) have shown positive self-degradation compared to neat PLA and more degradation was visible using landfill burial than natural weathering condition with almost 15 – 19% and 2 – 4% weight loss respectively after 6 month exposure. Due to slow degradation on natural weathering condition, KBC and KCC are useful for self-degraded materials for outdoor application.
