Amine-Catalyzed Propylene Oxide Polyether Alcohols
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Solution Overview
Problem
Polyether alcohols prepared with ethylene oxide have high viscosity, making them difficult to process in polyurethane systems and reducing compatibility with blowing agents, while those using exclusively propylene oxide have high viscosities and require complex catalyst work-ups.
Innovation Solution
A process involving the reaction of aromatic amines with propylene oxide in the presence of an amine catalyst, where propylene oxide comprises at least 90% of the alkylene oxide, and using an amine catalyst to achieve low viscosity polyether alcohols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If ethylene oxide is used in the polyether chain, then viscosity is reduced, but compatibility with blowing agents deteriorates
Solution Approach 1:
The patent extracts ethylene oxide from the alkylene oxide mixture, using exclusively propylene oxide to eliminate the compatibility problem while managing viscosity through catalytic optimization rather than ethylene oxide addition
Solution Approach 2:
The patent changes the catalytic parameters by using amine catalysts instead of traditional base catalysts, which enables exclusive propylene oxide polymerization at lower temperatures and achieves low viscosity without ethylene oxide
2Reliability
If exclusively propylene oxide is used, then compatibility with blowing agents is improved, but viscosity increases significantly
Solution Approach 1:
The patent changes the catalytic parameters from traditional base catalysts to amine catalysts, which dramatically reduce the viscosity of propylene oxide polyethers by enabling more efficient polymerization at lower temperatures and producing polyols with different molecular structures
Solution Approach 2:
The patent replaces the traditional mechanical mixing and high-energy polymerization process with amine-catalyzed polymerization that proceeds under milder conditions, producing lower viscosity products
3Productivity
If alkali metal hydroxides are used as catalysts, then reaction rate is improved, but work-up complexity increases
Solution Approach 1:
The amine catalyst remains in the final polyol product without requiring removal, as it becomes part of the molecular structure. This eliminates the need for neutralization and filtration steps required when using alkali metal hydroxide catalysts
Solution Approach 2:
The patent takes out the need for catalyst removal steps by using an amine catalyst that is incorporated into the product rather than requiring separation
4Force
If high proportions of costarters are used to reduce viscosity, then viscosity is reduced, but functionality and aromatic content deteriorate
Solution Approach 1:
The patent changes the catalytic parameters to use amine catalysts, which enable low-viscosity propylene oxide polyethers to be produced without adding costarters, thereby maintaining high functionality and aromatic content
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 process results in polyether alcohols with low viscosity and reduced unreacted aromatic amines, enhancing processability and compatibility with blowing agents, leading to improved flowability and storage stability in polyurethane systems.
Implementation Method 1
the use of amine catalysts gives polyols based on aromatic amines, in particular TDA, which have a low viscosity and comprise only propylene oxide as alkylene oxide
Data Source
AI summary
The invention relates to a process for preparing polyether alcohols by reacting a) aromatic amines with b) alkylene oxides in the presence of c) a catalyst, wherein the alkylene oxide b) comprises at least 90% by weight, based on the weight of the component b), of propylene oxide and an amine is used as catalyst c).