U.S. Department of Defense


Date of this Version



Chemical Physics Letters 637 (2015) 103–109


Cross-linked polymer networks are widely used as structural and protective materials, which requirestrength and toughness. Experiments have shown that cross-linked poly(dicyclopentadiene) (pDCPD)networks provide similar strength but superior fracture toughness relative to commonly-used networkchemistries like epoxy. To better understand pDCPD, we use atomistic molecular dynamics to study theproperties of pDCPD networks across the glass transition as a function of molecular weight between cross-links. Moreover, we identify molecular mechanisms that potentially control mechanical and transportproperties. The alpha-relaxation (the glass transition) is linked to intra-chain motions and large-scalesegmental motions, while sub-Tg are linked with more localized motions.