Natural fibers are widely used as reinforcement in composites. Pine needles are one of the major biowaste generated by Pinus roxburgii plant. This species found abundantly in the forests of Himachal Pradesh. In this work composites of urea-resorcinol-formaldehyde (URF) reinforced with pine needles fibers were prepared. Pine needles fibers were chemically modify to improve their compatibility with matrix. Pine needles were mercerized with NaOH solution and acetylated in order to increase their hydrophobic character. The chemically modified fibers were characterized with FTIR, 13C nuclear magnetic resonance (13C NMR) spectroscopy and SEM. The composites were prepared with treated and untreated fibers containing 30% fibers by weight using compression molding technique. The morphology of the materials thus obtained was evaluated by SEM. The chemical modifications of fibers improve fiber- matrix adhesion and also have markedly effect on mechanical properties of composites. Moreover the thermal resistance of these composites was improved on chemical modification. These results indicate that chemically modified fibers exhibit better compatibility with the polymer matrix than that of untreated fiber.
Polymer composites, Surface treatment, Pine needles, Thermosetting matrix