Linear polymerization of endo‐dicyclopentadiene initiated by metathesis catalysts

The polymerization of endo-dicyclopentadiene1 (endo-DCP) by the metathesis catalyst ReCl5/(CH3)4 Sn gave a substantial yield of a linear polymer with high molecular weight and high content of cis double bonds. The kinetics of the early stage of the reaction was studied by calorimetry. The polymerization proceeds via an oligomerization reaction followed by the formation of polymers. A mechanistic scheme is proposed to explain the generation of the primary active species and the two-step polymerization process.