Ultrastrong Polyketone Hot-Melt Adhesives Enabled by Ni-Catalyzed Carbonylative Polymerization

Conventional hot-melt adhesives (HMAs), such as poly(ethylene-co-vinyl acetate)s (EVA), are widely used in industries and daily life, yet their nondegradability raises environmental concerns after their lifecycle. In addition, their inadequate binding strength (<4.0 MPa) poses a fundamental limitation to engineering application. Transforming low-cost olefin feedstocks into high performance and degradable HMAs remains a significant challenge. Here, we report a novel polyketone adhesive through an earth-abundant nickel catalyst mediated carbonylative polymerization of ethylene with α-olefin. By elucidating the fundamental relationship between polyketone compositions and adhesion properties, we found that propylene/CO content significantly impacts the adhesive strength, and a facile composition regulation to employ biomass-sourced undecenoic acid monomer imparts a remarkable adhesive strength of up to 24.4 MPa on ceramic substrate, far outperforming commercial EVA. Moreover, these polyketone adhesives exhibit strong adhesion to diverse substrates, and demonstrate excellent reusability, high-temperature resistance, and robust tolerance to various organic solvents under extreme conditions. Incorporating maximum carbonyl contents in both of crystalline and amorphous domains enables efficient stress transfer within adhesive system to achieve high strength, and it also endows the resulting adhesives with desirable photodegradability.