The effect of acid hydrolysis treatment on the mechanical properties of oil palm empty fruit bunches (OPEFB) fibers/thermoplastic starch

Oil Palm Empty Fruit Bunches (OPEFB) fiber is a byproduct of the palm oil industry, and have the potential as a reinforcement material in various polymer based products, resulting in remarkable improvements in mechanical properties. In recent years, researchers have focused on developing OPEFB fiber reinforced thermoplastic starch (TPS) films as a potential alternative to petroleum based plastic films. However, the mechanical properties of these films need to be improved for practical applications. One approach to improving the mechanical properties of OPEFB fibers/TPS films is acid hydrolysis (AH) treatment. TPS films were formed by the plasticization process, in which the structure of granule starch was devastated and reformed by water, and glycerin through the heating process. The OPEFB fiber were undergo AH treatment for reduced the size of particles, removed impurities, and enhanced the compatibility between the OPEFB cellulose, and the TPS matrix. The OPEFB cellulose was added to the TPS matrix to produce OPEFB(AH)/TPS bio composites by film casting. The TPS films with OPEFB(AH) fiber content in the range of 1wt% to 6wt% were prepared. The mechanical properties were studied by changing the content of OPEFB(AH) fiber added to the TPS matrix. Results show that the films achieved the highest tensile strength when 4wt% OPEFB(AH)/TPS were used to form bio composites films. This was due to the homogenous, and good distribution of OPEFB cellulose in the TPS matrix. The tensile strength reduces when the OPEFB(AH)/TPS fiber content was increased to 5wt%. The elongation at the break of films experienced a slightly reduced as the loading of OPEFB(AH) cellulose increased because the mobility of the starch chain was hindered by OPEFB(AH) cellulose. The morphology of different loading OPEFB(AH) cellulose with the TPS matrix was investigated using a scanning electron microscope (SEM).