Moisture-Controlled DMC Catalyst 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 36° and 47° without the 34° peak, using metal halides like zinc chloride and coordinating organic ligands such as tert-butyl alcohol.
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 controlling the moisture content of the DMC catalyst within a specific range (8,000 to 140,000 ppm) and adjusting the water content in the reaction system. This precise parameter control modifies the catalyst's performance characteristics, enabling high catalytic activity while suppressing the formation of ultra-high molecular weight impurities. The moisture content parameter is critical in determining the catalyst's selectivity and activity balance.
2Productivity
If DMC catalyst is used for epoxide polymerization, then polymerization rate is improved, but molecular weight distribution becomes narrow
Solution Approach 1:
The patent utilizes parameter changes by optimizing the moisture content of the DMC catalyst and the water content in the reaction system. These parameter adjustments enable the catalyst to achieve high polymerization rates while maintaining a balanced molecular weight distribution, resolving the trade-off between productivity and composition stability.
3Reliability
If moisture content of DMC catalyst is increased, then catalytic activity is maintained in high water environments, but ultra-high molecular weight impurities increase
Solution Approach 1:
The patent applies parameter changes by defining a specific moisture content range (8,000 to 140,000 ppm) for the DMC catalyst. This optimized parameter range enables the catalyst to maintain high activity in high water environments while suppressing the formation of harmful high molecular weight impurities. The moisture content parameter serves as a critical control variable for achieving both reliability and purity.
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 environments, and produces 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
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 20 = 36° and 2θ = 47°, but no diffraction peak at 2θ = 34°, in an X-ray diffraction pattern.