A comparative study on graft copolymerization of MMA onto wood fiber under microwave and conventional heating

Wood polymer composites (WPC) are gaining popularity and widespread usage due to an increased awareness of human population towards the importance of environmental effects and green eco-friendly materials. Mechanical properties of WPC could be improved through graft copolymerization of monomer onto wood fiber to improve interfacial bonding. In this study, a comparison of free radical graft copolymerization using microwave-assisted and conventional heating method was performed. Methyl methacrylate (MMA) monomer is used in graft copolymerization of Meranti wood using a free radical initiator system consisting of ferrous sulfate and hydrogen peroxide. Grafting reaction time was varied while other graft parameters were kept constant including monomer concentration, initiator molar ratio, reaction temperature and solvent volume. Maximum graft yield of 11.75% and 10.17% were obtained for water bath heated and microwave-assisted method respectively. The presence of grafted monomer was proven by FTIR spectra analysis. Thermogravimetric analysis performed on grafted wood fibers showed improved thermal resistance compared to ungrafted wood fiber.