Sustainable composites with self-healing capability: Epoxidized natural rubber and cellulose propionate reinforced with cellulose fibers

Aligned with the UN's Sustainable Development Goals (SDGs), self-healing elastomers stand out as a cutting-edge field in Rubber Science and Technology. These materials have the potential to reduce resource consumption, prolong the lifespan of infrastructure and products, and contribute to the Circular Economy. This study presents the development of bio-based self-healing elastomeric composites prepared from blends of epoxidized natural rubber (ENR) and cellulose propionate (CP) reinforced with cellulose fibers (CFs). The ENR/CP ratio was optimized, with a 70/30 ratio enhancing the tensile strength (TS) of the base rubber and slightly reducing the elongation at break. This blend demonstrated a TS healing efficiency of 75% after a temperature-driven healing protocol (200 bar at 150 degrees C during 12 h). Then, the CF content was varied to enhance both mechanical performance and self-healing capabilities. Remarkably, from medium-high (5 phr to 15 phr) CF content, healing efficiencies higher than 85% were observed with important improvements in the mechanical performance. The self-healing process was attributed to the synergistic interplay between the polymeric chain mobility and the formation of hydrogen bonds. This innovative approach promises materials with extended lifespans, mechanical robustness, and repairability, underscoring the commitment to SDGs 9, 11, 12, 13, 14, and 15.Highlights Matrix of epoxidized natural rubber (ENR) and cellulose propionate (CP) blends. Cellulose fibers (CFs) reinforced the ENR/CP 70/30 optimized blend. CF addition increases tensile strength (TS) by up to 60%. Healing efficiency over 85% achieved with 5 phr to 15 phr CFs content. Self-healing attributed to polymeric chain mobility and hydrogen bonds. Rubber composites based on epoxidized natural rubber (ENR) and cellulose propionate (CP) blends reinforced with cellulose fibers (CFs) with self-healing capability driven by polymeric chain mobility and hydrogen bonds. image