A Single-Atom Upgrade to Polydicyclopentadiene

Chemical cross-links within polymers increase me-chanical strength and rigidity. Such cross-links can be either irreversible (e.g., those derived from carbon-carbon bonds) or reversible (e.g., those that depend on X-H center dot center dot center dot O hydrogen bonds). Here we describe a ketone-functionalized derivative of polydicyclo-pentadiene that establishes an unprecedented network of vinyl C- H center dot center dot center dot O hydrogen bonds within the polymer. The resulting thermoset displays a significantly increased glass transition temperature relative to the unfunctionalized polymer, together with enhancements to storage modulus, Young's modulus, and compression strength.