DMC Catalyst Moisture and Crystal Control for Cleaner Epoxide Polymerization
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Solution Overview
Problem
Double metal cyanide complex catalysts (DMC) used in epoxide polymerization tend to produce ultra-high molecular weight components as impurities and have limited catalytic activity, leading to a narrow molecular weight distribution in polymers.
Innovation Solution
Control the moisture content and crystal structure of the DMC catalyst by adjusting the moisture content to 8,000 to 140,000 ppm and ensuring specific X-ray diffraction peaks at 2θ=36° and 2θ=47° without 2θ=34°, using zinc chloride or zinc bromide as the metal halide salt and tert-butyl alcohol as the organic ligand.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If DMC catalyst is used for epoxide polymerization, then catalytic activity is improved, but ultra-high molecular weight impurities are produced
Solution Approach 1:
The patent applies parameter changes by precisely controlling the moisture content of the DMC catalyst within the range of 8,000 to 140,000 ppm and adjusting the Mn/Mo ratio to 0.5 to 2.0. These parameter optimizations modify the catalyst's physical and chemical properties, enabling it to maintain high catalytic activity while suppressing the formation of ultra-high molecular weight impurities during epoxide polymerization.
Solution Approach 2:
The patent employs dynamics by adjusting the catalyst's moisture content and compositional ratios to create an optimized catalytic system. The controlled moisture content and Mn/Mo ratio dynamically balance the catalyst's activity and selectivity, allowing it to promote polymerization while minimizing unwanted side reactions that produce high molecular weight impurities.
2Productivity
If DMC catalyst is used for epoxide polymerization, then polymerization rate is increased, but molecular weight distribution becomes narrow
Solution Approach 1:
The patent utilizes parameter changes by optimizing the moisture content (8,000 to 140,000 ppm) and Mn/Mo ratio (0.5 to 2.0) of the DMC catalyst. These parameter adjustments create an optimal catalytic environment that enhances polymerization rate while broadening the molecular weight distribution, thereby resolving the contradiction between productivity and manufacturing precision.
3Productivity
If moisture content is reduced in DMC catalyst, then catalytic activity is improved, but catalyst becomes sensitive to water
Solution Approach 1:
The patent applies parameter changes by setting the moisture content within the optimal range of 8,000 to 140,000 ppm and adjusting the Mn/Mo ratio to 0.5 to 2.0. This controlled moisture content prevents the catalyst from being overly sensitive to water while maintaining high catalytic activity, effectively resolving the contradiction between productivity and reliability.
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 DMC catalyst achieves high catalytic activity with suppressed high molecular weight impurities, maintaining activity even in high water content environments and producing polymers with improved physical properties.
Implementation Method 1
coordinating an organic ligand to a reaction product obtained by reacting a metal halide salt with a transition metal cyanide compound
Implementation Method 2
Double metal cyanide complex catalysts are known as epoxide polymerization catalysts
Implementation Method 3
having diffraction peaks at 2θ=36° and 2θ=47°, but no diffraction peak at 2θ=34° in an X-ray diffraction pattern
Data Source
AI summary
The present invention pertains to a double metal cyanide complex catalyst having a moisture content of 8,000 to 140,000 ppm as determined by the Karl Fischer method, and having diffraction peaks at 2θ=36° and 2θ=47°, but no diffraction peak at 2θ=34°, in an X-ray diffraction pattern.