摘要:
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.
摘要:
A cross-metathesized product mixture is prepared by contacting a metathesis catalyst under metathesis conditions with a composition comprising two or more chemically distinguishable ethylenically unsaturated polymers, at least one of said ethylenically unsaturated polymers (first polymer) having from 0.001 to 50 mole percent unsaturation and at least one other of said ethylenically unsaturated polymers (second polymer) being an amorphous polymer having a Tg less than 0° C. and having from 0.001 to 5 mole percent unsaturation.
摘要:
Meta-block copolymers and a process for preparing a product mixture comprising meta-block copolymers by contacting a metathesis catalyst under metathesis conditions with a composition comprising two or more ethylenically unsaturated polymers, said unsaturation defining one or more polymer segments in each ethylenically unsaturated polymer, at least one polymer segment in at least one ethylenically unsaturated polymer being chemically distinguishable from at least one polymer segment in at least one other ethylenically unsaturated polymer, characterized in that each meta-block copolymer in the product mixture comprises a random distribution of said chemically distinguishable polymer blocks.
摘要:
Meta-block copolymers and a process for preparing a product mixture comprising meta-block copolymers by contacting a metathesis catalyst under metathesis conditions with a composition comprising two or more ethylenically unsaturated polymers, said unsaturation defining one or more polymer segments in each ethylenically unsaturated polymer, at least one polymer segment in at least one ethylenically unsaturated polymer being chemically distinguishable from at least one polymer segment in at least one other ethylenically unsaturated polymer, characterized in that each meta-block copolymer in the product mixture comprises a random distribution of said chemically distinguishable polymer blocks.
摘要:
Two or more chemically distinguishable ethylenically unsaturated polymers, at least one having from 0.001 to 50 mole percent unsaturation and at least one other having an expected Tg or measured Tm value greater than 100° C. are cross-metathesized to form thermoplastic elastomers having improved performance properties.
摘要:
Group 4 metal complexes useful as addition polymerization catalysts of the formula: wherein G1 is a group containing from 1 to 40 atoms not counting hydrogen; T is a divalent bridging group of from 10 to 30 atoms not counting hydrogen, selected from mono- or di-aryl-substituted methylene or silylene groups or mono- or di-heteroaryl-substituted methylene or silylene groups, wherein at least one such aryl- or heteroaryl-substituent is substituted in one or both ortho-positions with a secondary or tertiary alkyl-group, a secondary or tertiary heteroalkyl group, a cycloalkyl group, or a heterocycloalkyl group, G2 is a C6-20 heteroaryl group containing Lewis base functionality, M is the Group 4 metal, X″″ is an anionic, neutral or dianionic ligand group, x″″ is a number from 0 to 5, and bonds, optional bonds and electron donative interactions are represented by lines, dotted lines and arrows respectively.
摘要:
Group 4 metal complexes comprising a polyvalent, heteroaryl donor ligand and their use as components of olefin polymerization catalysts, especially suited for preparing propylene copolymer products having high isotacticity and low molecular weight, are disclosed.
摘要:
A supported catalyst composition and process for preparing high molecular weight polymers of one or more addition polymerizable monomers, especially propylene, said composition comprising: 1) a substrate comprising the reaction product of a solid, particulated, high surface area, metal oxide, metalloid oxide, or a mixture thereof and an organoaluminum compound, 2) a Group 4 metal complex of a polyvalent, Lewis base ligand; and optionally, 3) an activating cocatalyst for the metal complex.
摘要:
Group 4 metal complexes comprising a polyvalent, heteroaryl donor ligand and their use as components of olefin polymerization catalysts, especially suited for preparing propylene copolymer products having high isotacticity and low molecular weight, are disclosed.
摘要:
Group 4 metal complexes comprising a polyvalent, heteroaryl donor ligand and their use as components of olefin polymerization catalysts, especially suited for preparing propylene/ethylene copolymer products having high isotacticity and low molecular weight, are disclosed.