Construction and Mechanical Properties of Boron Carbide Paper-Based Composites

This study focuses on the construction and characterization of boron carbide (B₄C) paper-based composites as a potential neutron protection material. The composites were prepared using cellulose fiber as the matrix and B₄C as the main filler through pulping, papermaking, and drying processes. The effects of cationic polyacrylamide (CPAM) and cationic starch (CS) on the retention of B₄C and the mechanical properties of the composite were investigated. Results showed that the mechanical properties of the composite, including tensile strength and folding endurance, were influenced by the amount and particle size of B₄C. The tensile strength decreased rapidly with increasing B₄C content, dropping below 3 kN/m when the proportion exceeded 40 wt %. The addition of CPAM significantly enhanced the retention rate of B₄C particles in the composite, reducing the loss of B₄C in the white water. The addition of 1.0-1.5 wt % CS improved the mechanical properties, increasing the tensile strength by approximately 27% and the folding endurance by 24%. Structural characterizations using field-emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS) revealed that B₄C particles were well dispersed within the composite. XPS confirmed the presence of B-C bonds in the composite. The thermogravimetric analysis (TGA) results showed that the composite has good mass stability in the range of 100-220 °C. The Monte Carlo simulation results showed that under the irradiation of a 0.1 MeV neutron source, the shielding rate of the 1 cm-thick composite material can reach 46.92%.