Romp polymerization in the presence of peroxide crosslinking agents to

Abstract

Methods of forming polycycloolefins having high crosslink density are disclosed. Olefins are polymerized via a metathesis mechanism in the presence of a crosslinking agent and a catalyst. The crosslinking agent generally comprises a peroxide that decomposes into reactive species forming crosslinks during post-cure. The catalyst is a ruthenium or osmium carbene complex of the formula: ##STR1## wherein M is Os or Ru; R and R.sup.1 are independently selected from hydrogen or a hydrocarbon selected from the group consisting of C.sub.1 -C.sub.20 alkyl, C.sub.2 -C.sub.20 alkenyl, C.sub.2 -C.sub.20 alkynyl, C.sub.2 -C.sub.20 alkoxycarbonyl, aryl, C.sub.1 -C.sub.20 carboxylate, C.sub.1 -C.sub.20 alkoxy, C.sub.2 -C.sub.20 alkenyloxy, C.sub.2 -C.sub.20 alkynyloxy and aryloxy; X and X.sup.1 are independently selected from any anionic ligand; and L and L.sup.1 are independently selected from any neutral electron donor. Preferably, L and L.sup.1 are trialkylphosphine ligands and at least one of the alkyl groups on the phosphine ligand may be a secondary alkyl or cycloalkyl group, especially P(isopropyl).sub.3, P(cyclopentyl).sub.3 and P(cyclohexyl).sub.3. Preferred crosslinking agents are peroxides, such as t-butyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy) hexyne-3, di-tert-butyl peroxide, and 2,5-dimethyl-2,5-di-(tert-butylperoxy) hexane or mixtures thereof. Olefins may be cyclic (e.g., monocyclic, bicyclic or tricyclic) or acyclic. Norbornene or norbornene derivatives are especially preferred.