Waterborne Interfacial-Reinforcement Strategy for Sustainable Natural Rubber Latex Bioelastomers With Self-Healing, Crack Tolerance, and Multifunctional Durability.

Developing bio-based elastomers that combine mechanical robustness, crack tolerance, self-healing, and functional durability remains challenging. Here, we report a waterborne interfacial reinforcement and functionalization strategy to construct multifunctional natural rubber latex (NRL)-based bioelastomers. Ammonium persulfate (APS)-assisted treatment promotes interfacial coupling between NRL chains and cellulose nanofibers (CNFs), establishing nanofiber-mediated load-transfer and energy-dissipation pathways. ZnO nanoparticles introduce inorganic physical junctions that regulate interfacial stress transfer while providing UV shielding and antibacterial activity. The optimized NRL-g-CNF/ZnO composite exhibits a tensile strength of 9.68 MPa, toughness of 15.30 MJ·m-3, and efficient room-temperature self-healing, with tensile strength and toughness recovery of 96.9% and 92.8% after 48 h, respectively. The composite also shows pronounced crack tolerance, including a fracture energy of 32.5 kJ·m-2 and stable deformation of notched samples, together with improved short-term mechanical retention under the specified UV-aging conditions, antibacterial activity, a measurable soil-burial response, and preliminary cytocompatibility. This simple casting-based strategy provides a potentially scalable route to multifunctional bioelastomers with potential for selected packaging applications, protective coatings, antibacterial/UV-shielding films, and non-implantable flexible materials.