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

ABSTRACT 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.