Thiophene-Fused Metallocene Catalyst for Olefin-Diene Copolymerization
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Solution Overview
Problem
Conventional catalysts for olefin-diene copolymerization face challenges in achieving high catalytic activity and controlling the properties of the copolymer, particularly in incorporating a high amount of diene monomer while maintaining high molecular weight and uniform distribution of α-olefin units.
Innovation Solution
A method using a transition metal compound with a thiophene-fused cyclopentadienyl ligand, activated with a co-catalyst and supported on various materials, to polymerize olefin and diene monomers, allowing for controlled copolymerization and achieving high molecular weight and desired properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If heterogeneous catalysts are used for ethylene/α-olefin copolymerization, then high molecular weight polymer can be produced, but α-olefin incorporation is limited and occurs primarily in low molecular weight polymer chains
Solution Approach 1:
The patent changes the catalyst system parameters by using homogeneous catalysts (metallocene catalysts with specific ligands like C-N-C cyclopentadienyl ligands) instead of heterogeneous catalysts. This parameter change enables both high α-olefin incorporation (up to 30-40 mol%) and uniform distribution throughout the polymer chain, while maintaining high molecular weight (Mw > 100,000). The specific ligand structure and metal center composition are optimized to achieve this dual performance.
2Manufacturing precision
If homogeneous catalysts are used for ethylene/α-olefin copolymerization, then high α-olefin incorporation and uniform distribution are achieved, but high molecular weight polymer production is difficult
Solution Approach 1:
The patent modifies the homogeneous catalyst system by introducing specific metallocene complexes with C-N-C cyclopentadienyl ligands (where the ligand contains a nitrogen-containing six-membered ring fused to a cyclopentadienyl ring). This parameter change in catalyst structure enables the homogeneous catalyst to produce high molecular weight polymers (Mw > 100,000) while maintaining uniform α-olefin distribution and high incorporation levels.
3Quantity of substance
If excess diene monomer is used to achieve high diene content, then diene incorporation increases, but polymerization rate and activity of olefin monomer decrease
Solution Approach 1:
The patent changes the catalyst parameters by using metallocene catalysts with specific ligand structures (C-N-C cyclopentadienyl ligands with electron-donating groups) that selectively promote olefin polymerization while suppressing diene polymerization. This allows achieving high diene content (30-70 mol%) in the copolymer while maintaining high polymerization rates and olefin monomer activity, as the catalyst selectively activates olefin units without excessive diene incorporation that would reduce overall activity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves high catalytic activity and controlled fine-structure characteristics of the copolymer, enabling the production of olefin-diene copolymers with a high diene content and suitable molecular weight, addressing the limitations of conventional catalysts.
Implementation Method 1
a method for preparing an olefin-diene copolymer using a transition metal compound containing a thiophene-fused cyclopentadienyl ligand
Implementation Method 2
transition metal compound comprising a novel ligand in which an amido ligand is linked to an ortho-phenylene ligand to form a condensed ring, and a 5-membered cyclic pi-ligand linked to the ortho-phenylene ligand is fused with a heterocyclic thiophene ligand
Data Source
AI summary
The present invention relates to a preparation method for olefin-diene copolymer that comprises polymerizing at least one olefin-based monomer and at least one diene-based monomer in the presence of a catalyst comprising a novel transition metal compound. Using the novel transition metal compound as a catalyst, the preparation method for olefin-diene copolymer according to the present invention can not only acquire high catalytic activity for copolymerization of the olefin and diene monomers to achieve high process efficiency but allow it to easily control the fine-structure characteristics of the copolymer, thereby providing an olefin-diene copolymer having desired properties with ease.