Ring‐opening metathesis polymerization of exo‐dicyclopentadiene: Reversible crosslinking by a metathesis catalyst

Abstract
Exo‐Dicyclopentadiene has been polymerized by several well characterized, single‐component metathesis catalysts to provide soluble, linear, poly exo‐dicyclopentadiene. Under the best circumstances the polymerizations proceed in a living manner. The crosslinking of polymer chains which can occur under high monomer concentration has been investigated and determined to result from the secondary metathesis of the cyclopentene substituent.