Olefin polymerization processes featuring in situ blending of an oil extension

Abstract

High molecular weight elastomers, such as ethylene-propylene-diene monomer (EPDM) polymers, are conventionally formulated with a post-polymerization oil extension to mitigate their high Mooney viscosity. Post-polymerization oil extension adds to processing costs and precludes use of polymerization facilities lacking oil extension capabilities. A low molecular weight polymer may be co-produced with a high molecular weight elastomer containing the same monomers, where the low molecular weight polymer may function in place of conventional oil extension. Polymerization methods may comprise: combining one or more olefinic monomers, a metallocene first catalyst component and a non-metallocene transition metal second catalyst component, and a solvent; and reacting the one or more olefinic monomers under solution polymerization conditions to form a polyolefin blend comprising first and second polyolefins having a bimodal molecular weight distribution. The non-metallocene second catalyst component may be a pyridylbisimine, quinolinyldiamido, pyridylamido, phenoxyimine, or bridged bi-aromatic complex.