Intelligent lignin-based elastomer biocomposite with strain-adaptive stiffening and thermally tunable modulus

Eco-friendly and intelligent elastomer materials with strain-adaptive stiffening and thermo-adjustable modulus are promising for safe tire applications, yet their preparation remains challenging. Herein, inspired by the lignin role in bridging cellulose and hemicellulose in plants and the self-strengthening of skeletal muscles by physical exercise, high performance eco-friendly and intelligent elastomer composite is prepared by rearrangement of interfacial hydrogen bonds via a repetitive mechanical training process. Biomass lignin is incorporated as a bridging agent for the construction of interfacial hydrogen bonds between silica filler and bromobutyl rubber matrix. The incorporation of lignin decreases 40% usage of silane coupling agent, 25% usage of silica for elastomer biocomposite. After mechanical training, the ordered hydrogen bond networks are formed among fillers, which endow the elastomer biocomposite with excellent strain-adaptive stiffening performance (elastic modulus increasing from 1.0 MPa to 24.7 MPa during deformation) and thermally tunable modulus (reversible variations between 2.0 MPa and 3.2 MPa). In this work, we show a facile strategy for the fabrication of eco-friendly intelligent elastomer biocomposite using easily available green raw materials.