Mechanical and physical properties of rice straw fiber-reinforced polypropylene composite

Abstract

In this study, the composite made of rice straw fiber and polypropylene as the adhesive has been produced. The mechanical properties (modulus of rupture, modulus of elasticity, compressive strength) and physical properties (density and thickness swelling) of composite samples have been examined for various compositions of rice straw fibers. The highest modulus of rupture of our composite is found to be 113 kgf/cm² obtained at the composition of rice straw fiber 40 wt. % and polypropylene 60 wt. %. The highest modulus of elasticity of our composite is 3.5×10⁴ kgf/cm² obtained at the composition of rice straw fiber 30 wt. % and polypropylene 70 wt. %. The modulus of elasticity tends to decline when the composition of rice straw is increased. The highest compressive strength and density are 8.9 MPa and 0.6 g/cm³, respectively, which are obtained at the formation of rice straw 60 wt. % and polypropylene 40 wt. %. Both compressive strength and density tend to increase when the composition of rice straw fiber is increased. The thickness swelling of the sample was obtained in the range of 0.5 to 1.0 %. Our composites (for all rice straw fiber compositions) have met Indonesian National Standard requirements for particleboard. Based on our results, we recommend producing a composite of rice straw fiber and polypropylene adhesive with an arrangement of 60 wt. % rice straw fiber and 40 wt. % polypropylene.