High-Molecular Weight Polyether Synthesis via Supported Catalyst
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Solution Overview
Problem
The existing method for preparing high-molecular weight allyl alcohol polyoxyethylene polyoxypropylene ether is inefficient, requiring a complex refining process that results in slow production cycles, resource waste, and secondary pollution due to excessive adsorbent waste.
Innovation Solution
A preparation method using a supported catalyst Rb-NHPA in a high-pressure reaction kettle with nitrogen gas, where ethylene oxide and propylene oxide are reacted with allyl alcohol, followed by acetic acid neutralization and filtration, omitting the need for a refining process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a two-step method with traditional catalysts (Na, K, or their hydroxides/methoxides) is used to prepare high-molecular weight allyl alcohol polyoxyethylene polyoxypropylene ether, then the molecular weight can be increased to >3000, but the filtering speed becomes extremely slow, production cycle becomes longer, and a large number of adsorbent waste residues are generated
Solution Approach 1:
The patent changes the catalyst from traditional alkali metal-based catalysts (Na, K, methoxides) to an organic tin catalyst (tin(II) 2-ethylhexanoate). This parameter change in catalyst type fundamentally alters the reaction mechanism and product properties, enabling high molecular weight polyether synthesis with significantly improved filtering characteristics and reduced adsorbent waste, thus resolving the contradiction between molecular weight and productivity
Solution Approach 2:
The patent employs a catalyst system that does not require complex post-treatment and adsorption processes. The organic tin catalyst allows the reaction to proceed without generating persistent harmful residues that would require extensive filtering and adsorption, thereby eliminating the need for large amounts of adsorbent materials and reducing production cycle time
2Manufacturing precision
If a complicated post-treatment process is used to remove residual alkali metal ions, then the product purity is improved, but the process complexity increases, production cycle becomes longer, and resource waste occurs due to adsorbent consumption
Solution Approach 1:
The patent extracts or eliminates the harmful alkali metal catalyst system from the process entirely by replacing it with an organic tin catalyst. This removal of the problematic catalyst type eliminates the need for complex post-treatment processes including deionization, neutralization, and adsorption, thereby simplifying the overall process while maintaining product purity
Solution Approach 2:
The patent uses an alternative catalyst system (organic tin catalyst) that replicates the catalytic function needed for polyether synthesis without producing the harmful side effects of alkali metal catalysts. This substitution allows the reaction to proceed with minimal post-treatment requirements, reducing process complexity while achieving the desired product purity
3Manufacturing precision
If a large number of adsorbent materials are used for filtering and adsorption, then the residual ions are removed effectively, but resource waste occurs and secondary pollution is generated
Solution Approach 1:
The patent converts the harmful effect of catalyst residue by choosing a catalyst (organic tin catalyst) whose residues are less harmful and do not require extensive adsorption treatment. The catalyst system is selected such that any remaining traces do not interfere with subsequent reactions or product performance, thereby eliminating the need for large amounts of adsorbent materials and preventing secondary pollution from adsorbent waste
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 method significantly reduces process time, retains high double bond retention rates, minimizes by-products, and allows for catalyst recycling, reducing waste and environmental impact while maintaining molecular weight and functional properties.
Implementation Method 1
adding an allyl alcohol raw material and a supported catalyst Rb-NHPA into a high-pressure reaction kettle
Implementation Method 2
dropwise adding an acetic acid into the reaction kettle so that the crude product of the high-molecular weight allyl alcohol polyoxyethylene polyoxypropylene ether is neutralized to be neutral
Implementation Method 3
removing a low-boiling point substance in vacuum
Data Source
AI summary
Related are a high-molecular weight allyl alcohol polyoxyethylene polyoxypropylene ether and a preparation method. During preparation, an allyl alcohol raw material and a supported catalyst Rb-NHPA are firstly added into a high-pressure reaction kettle, and it is heated after being replaced with a nitrogen gas; then after the internal temperature of the reaction kettle is raised to a reaction temperature, an ethylene oxide (EO) and propylene oxide (PO) mixture is continuously fed for a reaction; and finally, after the internal temperature of the reaction kettle is reduced, an acetic acid is dropwise added into the reaction kettle so that the crude product of the high-molecular weight allyl alcohol polyoxyethylene polyoxypropylene ether is neutralized to be neutral. The refining process of a polyether is omitted, the process flow is greatly simplified, and the process time is effectively saved. In addition, the supported catalyst Rb-NHP may be recycled.