A highly efficient metal-free protocol for the synthesis of linear polydicyclopentadiene.

We have achieved breakthroughs for the efficient synthesis of linear polydicyclopentadiene (pDCPD) via photoredox mediated metal-free ring-opening metathesis polymerization (MF-ROMP). Molecular weight control from 1 to 16 kDa can be targeted in a straightforward manner. Assisted by this method, the Tg–Mn dependence of linear pDCPD is investigated and reported for the first time.