Metallocene complex and preparation method therefor, catalyst composition, olefin polymerization method and olefin polymer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catalyst systems struggle to efficiently copolymerize ethylene and conjugated dienes, particularly in achieving high cis-1,4-structure content, high molecular weight, and narrow molecular weight distribution in conjugated diene polymers, while also facing challenges in using ethylene as a cost-effective alternative to butadiene.
Innovation Solution
A metallocene complex with a specific structure, prepared via a one-pot method using a heterocyclic compound and amine, exhibits improved catalytic activity and structural regularity control, enabling effective copolymerization of ethylene and conjugated dienes, with a catalyst composition that includes a cocatalyst for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional catalyst systems are used for copolymerization of ethylene and conjugated dienes, then the polymerization reaction can proceed, but the catalytic activity is insufficient and the structural regularity control capability is poor
Solution Approach 1:
The patent introduces heterocyclic fusion at specific positions of the metallocene ligand structure to create localized electronic and steric effects. This local modification of the catalyst structure enhances both catalytic activity and structural regularity control by creating specific interaction sites with the monomers during polymerization
Solution Approach 2:
The patent systematically varies the substituent groups (R1-R10) on the metallocene ligand, including different alkyl, aryl, and heteroatom combinations, to optimize the electronic and steric parameters of the catalyst. These parameter changes enable fine-tuning of both catalytic activity and the ability to control polymer microstructure
2Manufacturing precision
If complex multi-step synthesis methods are used to prepare metallocene complexes, then the catalyst structure can be precisely controlled, but the operational complexity and cost increase
Solution Approach 1:
The patent combines multiple synthesis steps into a one-pot procedure where the metallocene ligand is formed and coordinated to the metal center in a single reaction vessel. This merging of steps simplifies the overall process while maintaining precise structural control through carefully designed reagent addition sequences
Solution Approach 2:
The patent employs pre-formed lithiated heterocyclic compounds and pre-designed metallocene precursors that are prepared in advance with specific functional groups. These preliminary preparations enable the final complex formation to proceed in a single step with high structural fidelity
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 metallocene complex achieves high structural regularity and efficient copolymerization of ethylene and conjugated dienes, producing polymers with a high cis-1,4-structure content and controlled molecular weight distribution, while simplifying the synthesis process and reducing operational complexity and cost.
Implementation Method 1
Metallocene complexes refer to compounds in which a central metal is coordinated with one or more cyclopentadienyl or a derivative thereof, and play a very important role as a catalyst in various polymerization reactions
Data Source
AI summary
A metallocene complex and a preparation method therefor, a catalyst composition, an olefin polymerization method and an olefin polymer are provided. The metallocene complex has a structure of formula I. The catalyst composition containing the metallocene complex shows an improved catalytic activity, and also has relatively high structural regularity control capability for a conjugated diene structural unit and a relatively high capability for copolymerizing ethylene and conjugated diene.