Sulfur-Free Crosslinking of Diene Rubbers Enabled by Ring-Opening Metathesis Polymerization

Environmental benignity and sustainable development represent pivotal challenges confronting the contemporary rubber industry. Herein, ring-opening metathesis Polymerization (ROMP) is developed as a green crosslinking strategy for diene-based rubbers. Employing liquid chloroprene rubber (LCR) as a model system, dicyclopentadiene (DCPD) and 1,5-cyclooctadiene (COD) are utilized as cycloolefin comonomers to copolymerize with LCR via olefin metathesis (OM) reactions. Upon the precise modulation of the stoichiometric ratios of DCPD, COD and LCR, effective control over the architecture of the crosslinked network can be achieved for tunable mechanical properties. The obtained composites exhibit exceptional mechanical performance, manifesting a maximum tensile strength of 288.89 kPa coupled with an elongation at break of 193.72%. Further elucidation of the reaction mechanism confirmed that LCR actively participates in copolymerization via OM, rather than undergoing mere physical blending. This mechanistic insight establishes a fundamental theoretical framework for advancing sustainable rubber recycling technologies and pioneers novel pathways for the value-added modification of LCR and the rational design of multifunctional composite materials.