ALKALI TREATMENT ON SUGARCANE BAGASSE TO IMPROVE PROPERTIES OF GREEN COMPOSITES OF SUGARCANE BAGASSE FIBERS-POLYPROPYLENE

This work evaluated the improved performance of sugarcane bagasse fibers-polypropylene (PP) composites as a result of alkali treatment done on sugarcane bagasse as reinforcing fibers. Alkali solution of 10 NaOH with a temperature of 60-70oC was used to soak the bagasse for 2 to 6 hours. Hot pressed samples were prepared from a mixture of sugarcane bagasse fibers and PP with fibers/PP weight ratios of 20/80, 25/75, and 30/70. Hot pressed samples using untreated bagasse fibers were also produced for a comparison. Tensile test was performed to all samples and the fracture surface from tensile test samples were observed using scanning electron microscopy (SEM) to study how the presence of reinforcement in PP matrix and its alkali treatment influenced the strengthening and failure characteristics of the composites. The alkali treatment carried out resulted in a relevant increase of tensile strength of the composite to 229,29 MPa at 20/80 fibers/PP weight ratio or an increase of 43 comparing to the composite samples which their fibers were untreated with alkali. The tensile strength of the composite with a 25/75 fibers/PP weight ratio increased to 290,30 MPa and decreased to 214,17 MPa as the fibers/PP weight ratio increased to 30/70. Microstructural study using SEM showed a different outlook on the fiber#65533s surface after alkali treatment which the treatment caused the elimination of the impurities, waxy materials, lignin as well as hemicellulose, which was responsible for an easy deformation of the cellular networks. Alkali treated-sugarcane bagasse gave the best reinforcement for composites after 2 hours of treatment which resulted in the excellent fiber-resin bonding