Isolation and Characterization of Cellulose Fibers from Rice Straw and its Application in Modified Polypropylene Composites

In this work, cellulose fibers from rice straw were isolated by a mechanical–high pressure steam technique, and were filled into polypropylene (PP) as a modifier. The structure and morphology of untreated and treated rice straw fibers were characterized by using Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X–ray diffraction (XRD). The thermal properties, rheological behaviors and mechanical properties of the PP composites filled with untreated and treated straw fibers were investigated. The results show that the hemicelluloses and lignin can be removed from the structure of fibers by pretreatment. XRD curves reveal that this results in improving the crystallinity of the fibers. Compared with untreated rice straw fibers, PP composites filled with treated rice straw fibers exhibit higher thermal stability. The complex viscosity values of the composites decrease because of the pretreatment. Pretreatment can significantly improve tensile strength, elongation at break and impact strength of PP/rice straw fibers composites due to its enhanced interfacial adhesion between the PP matrix and rice straw fibers.