Abstract: Crosslinked polydicyclopentadiene polymer and copolymer are made by first forming a thermoplastic polymeric intermediate in a ring-opening metathesis polymerization (ROMP), and then crosslinking the intermediate in a melt-processing or solution processing step. The formation of the intermediate permits facile removal of residual monomer, which leads to a reduction in odor and improvement in physical properties. Crosslinking can be achieved using various crosslinking strategies, including further ROMP reactions, addition polymerization of residual double bonds, addition of a crosslinking agent or introduction of functional groups.

Abstract: Catalyst compositions that are highly tolerant of catalyst poisons for use in addition polymerizations comprising a catalytic derivative of a Group 4 metal complex, a cocatalyst, and a Group 13 metal amide compound.

Abstract: Cyclic oligomers containing ester linkages are polymerized in the presence of a catalyst having at least one oxygen atom bonded to two metal atoms. At least one of the metal atoms is a tin atom, which is preferably tetravalent, i.e., bonded to three other groups in addition to the oxygen atom. The other metal atom may also be another tin atom, which is again preferably tetravalent, or a zinc, aluminum or titanium atom. The catalyst may contain multiple oxygen atoms that are bonded to two such metal atoms as described. These catalysts are active, efficient polymerization catalysts. They are often liquids at polymerization temperatures. The catalysts can be formed in situ in the polymerization process, which provides additional flexibility in the process and increased storage stability of starting materials.

Abstract: A process for preparing interpolymers of ethylene and one or more C3-8 olefin monomers comprising contacting a monomer mixture comprising ethylene and one or more C3-8 olefin monomers with a catalyst composition comprising a Group 4 metal complex of a polyvalent, Lewis base ligand under addition polymerization conditions.

Abstract: Cyclic oligomers containing ester linkages are polymerized in the presence of a dialkyltin di(carboxylate) catalyst. The catalyst provides a latency period followed by a rapid polymerization to form a high molecular weight polymer.

Abstract: Metal complexes, catalysts derived therefrom, and polymerization processes using the same, characterized by the presence of one or more nitrogen and boron containing, anionic 5-membered cyclic ligand groups, especially 1,2-azaborolyl groups, are disclosed.