No abstract

The increase of environmental awareness has led to interest in the use of materials with eco-friendly attributes. In this study, a sandwich composite was developed from polyester and kenaf fiber with various orientation arrangements. Polyester/kenaf sandwich composite was fabricated through the combination of a hand lay-up process and cold compression. The tensile, flexural, and Izod impact tests of the sandwich composites were evaluated by using a universal tensile tester and an impact tester. The thermal stability of polyester/kenaf sandwich composite and plywood were investigated by using a thermogravimetric analyser. Results showed that the polyester/kenaf sandwich composite with kenaf fiber in anisotropy orientation achieved the highest mechanical properties. The kenaf fiber in anisotropic orientation could absorb the impact energy and allow the sandwich composite to withstand greater impact forces compared to composite with fiber in perpendicular or isotropic orientations. The polyester/kenaf sandwich composite also showed higher thermal stability compared to a conventional plywood sheet. Thus, the fabrication of polyester/kenaf sandwich composite with kenaf fiber in an anisotropic orientation design has great potential to replace plywood sheets for beam construction applications.

Supported nickel oxide based catalysts of Fe/ Co/ Ni (10: 30: 60)-Al₂O₃ and Pr/ Co/ Ni (5: 35: 60)-Al₂O₃ that were prepared by wetness impregnation method showed potential catalysts for the in-situ reactions of H₂S desulfurization and CO₂ methanation from ambient temperature up to 300 ^oC.  X-ray Photoelectron Spectroscopy revealed Ni₂O₃ and Fe₃O₄ as the surface active components on the Fe/ Co/ Ni (10: 30: 60)-Al₂O₃ catalyst, while Ni₂O₃ and Co₃O₄ on the Pr/ Co/ Ni (5: 35: 60)-Al₂O₃ catalyst.  Energy Dispersive X-ray analysis indicated the presence of 2.7 % and 0.9 % of sulfur on the spent Fe/ Co/ Ni (10: 30: 60)-Al₂O₃ and Pr/ Co/ Ni (5: 35: 60)-Al₂O₃ catalysts, respectively.  N₂ adsorption-desorption analysis showed reduction of 5.5 % on the surface area of the spent Fe/ Co/ Ni (10: 30: 60)-Al₂O₃ catalyst. However, the surface area of the spent Pr/ Co/ Ni (5: 35: 60)-Al₂O₃ catalyst increased by 8.6 %.

Supported nickel oxide based catalysts were prepared by wetness impregnation method for the in-situ reactions of H 2 S desulfurization and CO 2 methanation from ambient temperature up to 300°C. Fe/Co/Ni (10:30:60)-Al 2 O 3 and Pr/Co/Ni (5:35:60)-Al 2 O 3 catalysts were revealed as the most potential catalysts, which yielded 2.9% and 6.1% of CH 4 at reaction temperature of 300°C, respectively. From XPS, Ni 2 O 3 and Fe 3 O 4 were suggested as the surface active components on the Fe/Co/ Ni (10:30:60)-Al 2 O 3 catalyst, while Ni 2 O 3 and Co 3 O 4 on the Pr/Co/Ni (5:35:60)-Al 2 O 3 catalyst.