Nanoconfined ring-opening metathesis polymerization of dicyclopentadiene

Abstract

Ring-opening metathesis polymerization (ROMP) of endo-dicyclopentadidene (DCPD) with second generation Grubbs catalyst is carried out under nanoscale constraint. Differential scanning calorimetry is used to study the polymerization reaction both in the bulk and in the nanopores of controlled pore glass as a function of heating rate. In 110 nm-diameter pores, DCPD undergoes incomplete polymerization followed by the reverse Diels-Alder reaction to form cyclopentadiene. Decreasing the heating rate shifts both exothem and endotherm reactions towards lower temperatures but does not avert the side reaction. In the bulk unconfined case, only the reverse Diels-Alder reaction occurs in the absence of catalyst. Under nanoconfinement, the ROMP reaction is slower in nanopores compared to bulk, whereas the reverse Diels-Alder reaction is faster in nanopores compared to the bulk.