The crosslinkable or crosslinked polymer composition 20 wherein the monomeric or oligomeric polyene comprises at least one member selected from {HEAD ~ the group} consisting of dicyclopentadiene, tricyclopentadiene, norbornadiene, norbornadiene dimer, {TAIL ~ hexahydronaphthalene} and dimethanohexahydronaphthalene 
consisting of
The crosslinkable or crosslinked polymer composition 20 wherein the monomeric or oligomeric polyene comprises at least one member selected from { HEAD ~ the group } consisting of dicyclopentadiene , tricyclopentadiene , norbornadiene , norbornadiene dimer , { TAIL ~ hexahydronaphthalene } and dimethanohexahydronaphthalene
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH