UV-induced 9-anthracenecarboxylic acid crosslinked epoxidized natural rubber elastomers with sustainable dual-responsive fluorescence and shape-memory functions

Stimuli-responsive flsuorochromic smart elastomers have substantial potential for intelligent information storage, anticounterfeiting and encryption applications, and flexible actuation applications. However, traditional fluorochromic elastomers have inherent limitations, including poor reprocessability, limited mechanical properties, and low crosslinking efficiency. To address these issues, we designed an ultraviolet (UV)-responsive biobased elastomer using epoxidized natural rubber (ENR) as the matrix and 9-anthracenecarboxylic acid (9-ACA) as a green photo-crosslinking precursor and a reinforcing component, without the need for additional catalysts. Under 365 nm UV irradiation, the anthracene rings in 9-ACA underwent [4 + 4] photocycloaddition, forming a high-density crosslinked network. This process increased the crosslinking density to 1.37 × 10 −4  mol/cm 3 , and strain-induced crystallization further enhanced the mechanical properties, with tensile strength and fracture energy reaching 8.49 MPa and 11.48 kJ/m 2 , respectively. Conversely, 254 nm UV irradiation caused dimer de-crosslinking, enabling reversible regulation of fluorescence (quenched under 365 nm and recovered under 254 nm) and shape-memory function. Compared with traditional diacid-crosslinked systems, the proposed UV-induced system demonstrated higher crosslinking efficiency and superior reprocessability (76.27% strength retention). Furthermore, information encryption simulations revealed reversible “hiding–reading–erasing” cycles. This study provides a feasible strategy for developing high-performance, sustainable smart elastomers, consistent with green material development goals.