Preparation of biomass-oxidized natural rubber/cellulose nanofibers composites with enhanced mechanical properties and self-healing properties based on hydrogen bonding network

The production of mechanically improved, self-healing composites from pure biomass materials through a simple and environmentally friendly process has become a major challenge and has attracted considerable attention. In this study, composites with enhanced mechanical characteristics, significant self-healing capabilities, and dye adsorption were prepared through synergistic hydrogen bonding between oxidized natural rubber (ONR) and cellulose nanofibers (CNFs). The composites exhibited improved compatibility with the CNFs filler due to the oxidation of the natural rubber (NR) matrix. Compared with the ONR, the mechanical strength (4.40 MPa) and toughness (10.69 MJ/m 3 ) of the ONR/CNFs-5 and NR/CNFs-5 composites increased by 37 % and 58 % and 125.64 % and 48.88 %, respectively. Furthermore, the composites rapidly achieved self-healing within 2 min at room temperature and exhibited exceptional self-healing performance (97.06 % stress recovery and 97.07 % strain recovery) within 48 h. In addition, the ONR/CNFs composites exhibited adsorption capacity for cationic dyes (5.10 mg/g for methylene blue (MB) and 177.20 mg/g for malachite green (MG)). These dyes were desorbed after adsorption with anhydrous ethanol, and the composites showed good reusability after five cycles, retaining 84.50 % efficiency for MB and 91.20 % for MG. • An ONR/CNFs composite with good mechanical properties and self-healing ability has been successfully developed. • The oxidation of NR creates a hydrogen bonding network between the matrix and the filler, improving their compatibility. • The enhanced mechanical and self-healing properties are due to the creation of a hydrogen bonding network. • At room temperature, the composite material heals quickly and efficiently. • After five cycles, the composite material retains its integrity and good adsorption efficiency.