Journal of Physical Science, Vol. 27(1), 1–14, 2016 © Penerbit Universiti Sains Malaysia, 2016 The Effect of the Chemical Modification of Wood Fibre Using Salicylic Acid and Ethanol on the Properties of Recycled High Density Polyethylene/Wood Fibre Composites Supri Abdul Ghani, 1* Mohamad Hanif Mohd Pisal, 2 Firuz Zainuddin 2 and Hanafi Ismail 3 1 Faculty of Engineering Technology, Universiti Malaysia Perlis, Main Campus, Pauh Putra, 02600, Perlis, Malaysia 2 School of Materials Engineering, Universiti Malaysia Perlis, Kompleks Taman Muhibah, Jejawi-2, 02600, Perlis, Malaysia 3 School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia * Corresponding author: supri@unimap.edu.my Abstract: The effect of the chemical modification of wood fibre (WF) using salicylic acid/ethanol on the tensile properties, water absorption, thermal degradation and morphology of recycled high density polyethylene/WF (rHDPE/WF) composites was studied. Both of the composites: rHDPE/WF and rHDPE/WF M (modified with salicylic acid and ethanol) were prepared using a Brabender Plasticorder at 160°C with a rotor speed of 50 rpm. The results indicate that the rHDPE/WF M composite has a greater tensile strength, a higher modulus of elasticity, greater thermal stability, greater resistance to water absorption and a lower elongation at break than the rHDPE/WF composite. SEM micrographs show that better interfacial adhesion occurs between the WF phase modified with salicylic acid and ethanol (WF M ) and the rHDPE phase in the rHDPE/WF M composite. Keywords: Recycled high density polyethylene, wood fibre, salicylic acid, polyethylene, ethanol 1. INTRODUCTION Renewable natural organic fibres that are biodegradable and ecofriendly act as reinforcing materials for glass or carbon fibre and as inorganic fillers. These fibres have high specific strengths and elastic moduli, low cost and low densities, and are renewable organic, non-hazardous, malleable, widely available and relatively unabrasive. 1,2 Yazid et al. 3 showed that the elastic moduli of rHDPE/NR/CFF composites increased with the fibre load in the blend, but the tensile strength and elongation at break decreased. Through studies and research, thermoplastic or natural fibre composites such as wood plastic composites (WPC) have been shown to have excellent qualities for technical applications such as load bearing. 4 Polyethylene, which is a polymer, has numerous applications in our modern world. Such polymers are frequently used in thermoplastics for the