Covalent-Hydrogen Bond Interface Design for Low Heat Generating, High Wear-Resistant, and Tear-Resistant Rubber

This study proposes a novel interface design strategy that simultaneously constructs covalent bonds and octuple hydrogen bonds at the interface between epoxidized natural rubber (ENR) and silica, synergistically enhancing the mechanical properties and dynamic durability of the composite material. To address issues such as poor dispersion of silica filler and weak interfacial bonding, the silica surface was epoxidized using γ-glycidoxypropyltrimethoxysilane (KH560) to create ESilica. A multifunctional hydrogen bond donor/acceptor cross-linker (dCB) was designed to react simultaneously with both ENR and ESilica, forming a hybrid composite interface structure incorporating both covalent bonds and dynamic hydrogen bonds. Experimental results demonstrate that, with the addition of 3 phr dCB, the tensile strength of the composite increased from 24.78 to 31.51 MPa, the fracture toughness rose from 66.95 MJ/m3 to 102.31 MJ/m3, the tear resistance improved by 70.24%, the wear resistance increased by 23.51%, and the compression heat buildup decreased by 27.2%, alongside significant enhancement in fatigue resistance. The performance improvement stems from covalent bonds providing high-strength interfacial bonding, while the octuple hydrogen bonds dissipate energy through a reversible break/reform mechanism, suppressing crack propagation and heat accumulation, and endowing the material with a degree of self-recovery capability. This composite interfacial structure effectively disperses stress through hierarchical fracture mechanisms, substantially boosting the mechanical properties and dynamic durability of the rubber composite. This work provides an important scientific foundation and practical solution for developing next-generation green rubber composites characterized by low heat generation, high wear resistance, and extended service life.