Influence of acetosolv and eco-friendly bleaching treatment of orange bagasse in biocomposite properties: a mechanical and thermal approach

The development of efficient pre-treatments in biobased products has been used to add value to the residue. For that purpose, this work aims to carry out fibers chemically extracted from the orange bagasse (Citrus sinensis) as reinforcement in polymeric matrix composites. The fibers were extracted by acetosolv, following two bleaching steps to obtain fibers with properties that promote their use in the polymer matrix. Three specimen configurations were carried out: orange bagasse untreated (OBU), orange bagasse untreated-acetosolv (OBAc), and acetosolv-bleaching (OBAc-B). All composites were characterized by chemical composition, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Biocomposites were prepared using a HIPS matrix with 15% reinforcement and chemically extracted orange bagasse fibers (OBU, OBAc, OBAc-B). XRD data showed that the OBAc-B has higher crystallinity indexes than OBU (15.1-48.3% OBAc-B). The mechanical behavior of composites presents an oscillation in tensile strength, elastic modulus, and strain as a function of the most appropriate reinforcement treatment, i.e., acetosolv without bleaching. Results indicate that all treatment factors used in this work contribute to the fiber characteristics (mechanical, chemical, and thermal behavior) as a promising approach to extract cellulose fibers from orange bagasse and use them as a reinforcement in polymer matrix application.