Pyridine Bis(Phenylenephenolate) Catalysts for Non-Aromatic Solubility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catalyst systems face challenges in maintaining high catalyst activity and molecular weight capability at high reactor temperatures, and there is a need for catalysts that are soluble in non-aromatic solvents to produce a wide range of polyolefin products, such as polyethylene and polypropylene, while being thermally stable.
Innovation Solution
Development of bis(aryl phenolate) Lewis base transition metal complexes with improved solubility in non-aromatic hydrocarbons, such as isohexane, which maintain catalyst performance and stability at varying reactor conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If aromatic solvents are used to dissolve catalyst components, then solubility is improved, but environmental and safety concerns increase due to aromatic solvent usage
Solution Approach 1:
The patent modifies the ligand structure by introducing long alkyl chains (C10-C20) at specific positions (R4 and R5) to change the solubility parameters of the catalyst complex, enabling it to dissolve in non-aromatic aliphatic hydrocarbons instead of requiring aromatic solvents
Solution Approach 2:
The patent creates a new class of catalyst complexes that replicate the functional properties of aromatic-soluble catalysts while using non-aromatic solvents, effectively copying the performance without the harmful aromatic solvent dependency
2Productivity
If reactor temperature is increased to improve polymerization rate, then productivity increases, but catalyst stability and molecular weight capability decrease
Solution Approach 1:
The patent creates a composite catalyst system combining a transition metal complex with a specifically designed bis(aryl phenolate) ligand that has both electron-donating and sterically demanding properties, creating a synergistic effect that maintains stability at elevated temperatures while preserving activity
Solution Approach 2:
The patent introduces long alkyl chains at specific positions (R4 and R5) of the ligand to create localized steric bulk that protects the metal center from degradation at high temperatures, while other parts of the ligand maintain electronic properties for high activity
3Manufacturing precision
If catalyst activity is increased to produce high molecular weight polymers, then product quality improves, but catalyst stability at high temperatures deteriorates
Solution Approach 1:
The patent optimizes the ligand's electronic parameters through the pyridine-2,6-bis(phenylenephenolate) structure with long alkyl chains, creating a balance where the metal center remains electronically active for high molecular weight polymerization while the steric environment provides thermal stability
Data Source
AI summary
Exemplary embodiments of the present technological advancement include pyridine-2,6-bis(phenylenephenolate) complexes that are useful as catalyst components for olefin polymerization and have improved solubility in non-aromatic hydrocarbons (e.g. isohexane). The improved solubility of these complexes was accomplished by the modification of the ligand framework at a specific position that led to improved solubility, but did not adversely affect the performance of the complex when used as a catalyst for olefin polymerizations.