Physical and mechanical characterization of surface treated bamboo fibers

The bamboo fiber has been studied as composite reinforcement for offering lightness and more resistance to the material. Alkalization and acetylation are superficial chemical treatments based on alkaline solution and on a solution based in acid and acetic anhydride, respectively, which modify the fibers composition, introducing functional groups acetyl, turning it hydrophobic. In this project, it was aimed the application of the alkalinization and acetylation treatments, attempting to improve the fibers adhesion to the polymers when in a composite. The fibers were evaluated by moisture content, water absorption tests by immersion, density, infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, tensile tests, and morphological analysis. When acetylated, the bamboo fiber presented lower water absorption (62.98%), gained thermal stability of approximately 50 °C, presented lower crystallinity (62.47%) and, according to SEM images, the fibers has shown an increase of surface roughness, facts that contribute to the best fiber/matrix adhesion in composites. The acetylation decreased the mechanical strength of the fiber, supporting 19,820 MPa, against 27,670 MPa from the natural and 31,730 MPa from the alkaline.