Investigation of mechanical and water absorption characterization of chitosan and rice bran reinforced biochar-based composites

This work investigated the innovative combination of biochar, chitosan, and rice bran as natural fillers in epoxy composites, prepared via the hand layup method. Mechanical tests revealed that sample A (90% epoxy, 10% chitosan) achieved the highest tensile strength (17.74 MPa), flexural strength (173.8 MPa), tensile modulus (8046.23 MPa), and flexural modulus (4933.56 MPa), with minimal water absorption (2.3255%) and porosity (0.130%). Sample B (90% epoxy, 8% chitosan, 2% biochar) showed decreased tensile strength (10.05 MPa) but improved flexibility (138.43 MPa). In contrast, sample E (90% epoxy, 10% biochar) exhibited the weakest performance, with tensile strength (7.723 MPa), highest porosity (0.555%), and maximum water absorption (9.0390%). The novelty of the work lay in the comprehensive analysis of the synergistic effects of these multi-filler compositions on mechanical properties and moisture resistance, with SEM micrographs revealed uniform filler dispersion and FTIR spectroscopy confirmed characteristic functional groups. This work provided valuable insights for optimizing eco-friendly composites for various applications.