Hybrid Polyester-Polyether Polyol Synthesis via DMC Catalyst Activation
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Solution Overview
Problem
The existing processes for producing hybrid polyester-polyether polyols face challenges with the activation of double metal cyanide (DMC) catalysts, leading to prolonged induction periods and reduced productivity due to inconsistent catalyst activation, often resulting in failed reactions and increased costs.
Innovation Solution
Incorporating a Group 3-Group 15 metal or lanthanide series metal compound, bonded to specific anions, in conjunction with a carboxylate initiator and DMC catalyst complex, to consistently activate the DMC catalyst, thereby reducing induction times and enhancing polymerization rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a DMC catalyst complex is used for polymerizing alkylene oxide, then fast polymerization and low terminal unsaturation are achieved, but the catalyst requires a prolonged induction period for activation which reduces productivity
Solution Approach 1:
The patent applies preliminary action by adding a small amount of water (0.01-5% by weight relative to alkylene oxide) before introducing the DMC catalyst complex. This pre-introduction of water serves to pre-activate the catalyst system, converting it from an inactive to an active state before the main polymerization begins. This preliminary activation step eliminates the prolonged induction period that would otherwise occur during the main reaction, thereby resolving the contradiction between achieving fast polymerization and minimizing activation time.
2Reliability
If the DMC catalyst is exposed to alkylene oxide to activate it, then the catalyst becomes active, but the activation process takes an indeterminate amount of time and may fail completely
Solution Approach 1:
The patent implements preliminary action by introducing water into the reaction system before adding the DMC catalyst complex. This pre-activation step with water ensures the catalyst is in its active form before the main polymerization begins. By performing this activation action in advance with a controlled amount of water, the patent eliminates the indeterminate and potentially failed activation process that occurs when alkylene oxide alone is used to activate the catalyst.
Solution Approach 2:
The patent applies parameter changes by controlling the amount of water present during catalyst activation to be within a specific range (0.01-5% by weight relative to alkylene oxide). This precise control of the water parameter ensures reliable and consistent catalyst activation. By optimizing this parameter, the patent transforms the unreliable, indeterminate activation process into a controlled, predictable process that consistently produces active catalyst without excessive time delays.
3Reliability
If the catalyst induction period is extended, then the catalyst may become fully activated, but productivity decreases due to the time required before polymerization begins
Solution Approach 1:
The patent applies preliminary action by performing catalyst activation with water before the main polymerization reaction begins. This pre-activation ensures the catalyst is fully activated in advance, so when the alkylene oxide polymerization starts, the catalyst is already in its optimal active state. This eliminates the need to extend the induction period during the main reaction, thereby maintaining high productivity while ensuring complete catalyst activation.
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
This approach ensures rapid and consistent activation of the DMC catalyst, leading to increased productivity, reduced manufacturing costs, and lower waste, as the catalyst remains active for faster alkylene oxide polymerization.
Implementation Method 1
The polymerization of the oxirane requires a catalyst. Among the catalysts that have been described for this polymerization include double metal cyanide (DMC) catalyst complexes... The presence of the Group 3 - Group 15 metal or lanthanide series metal (G3-15LA) compound makes for consistently rapid activation of the double metal cyanide catalyst complex
Implementation Method 2
polymerizing at least one alkylene oxide in the presence of (1) a carboxylate initiator compound... The oxirane polymerizes during the reaction to form polyether groups
Data Source
AI summary
Hybrid polyester-polyether polyols are prepared by polymerizing an alkylene oxide in the presence of a carboxylate initiator. The polymerization is catalyzed with a mixture of double metal cyanide catalyst complex and certain magnesium, group 3 - group 15 metal or lanthanide series metal compounds.