A Single-Atom Upgrade to Polydicyclopentadiene

Chemical cross-links within polymers increase mechanical 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···O hydrogen bonds). Here we describe a ketone-functionalized derivative of polydicyclopentadiene that establishes an unprecedented network of vinyl C–H···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.