Polyester-Polyether-Modified Polybutadienes via Direct Alkoxylation
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Solution Overview
Problem
Current processes for preparing polyether-modified polybutadienes are limited by the use of organometallic compounds, which are air and moisture sensitive, and result in low HLB values and branched polybutadiene structures, making it difficult to produce linear polybutadienes with pendant polyether chains through direct alkoxylation reactions.
Innovation Solution
A process involving the direct alkoxylation of pendantly hydroxy-functional polybutadienes with alkylene oxides, without using organometallic compounds, to produce polyether-modified polybutadienes with pendant polyether radicals, and further modifying these with cyclic anhydrides or lactones to form polyester-polyether-modified polybutadienes, enhancing their properties as adhesion promoters and defoamers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If organometallic compounds are used in the preparation process, then polyether-modified polybutadienes can be prepared, but the process becomes air and moisture sensitive and difficult to implement industrially
Solution Approach 1:
The patent replaces expensive and sensitive organometallic compounds with simple, inexpensive, and stable alkali metal hydroxides or double metal cyanide catalysts. These alternative catalysts are disposable in the sense that they don't require special handling conditions and can be used directly in industrial settings without complex protective measures, thereby eliminating air and moisture sensitivity while maintaining catalytic functionality.
Solution Approach 2:
The patent changes the chemical nature of the catalyst from organometallic compounds to alkali metal hydroxides or double metal cyanide catalysts. This parameter change in catalyst composition fundamentally alters the reaction conditions, allowing the process to proceed without air and moisture exclusion requirements, thus improving ease of manufacture and industrial feasibility.
2Adaptability or versatility
If OH-terminated polybutadienes are used in alkoxylation, then polyether-polybutadiene-polyether triblock structures are formed, but the HLB values remain low and miscibility with other reaction components is poor
Solution Approach 1:
The patent uses pendantly hydroxy-functional polybutadienes where hydroxyl groups are located at pendant positions along the polymer chain rather than at chain ends. This local quality change in functional group positioning allows the polyether chains to attach in comb-like structures, creating local regions of high polarity and hydrophilicity that significantly increase the overall HLB value and improve miscibility with other reaction components.
Solution Approach 2:
The patent creates a composite structure by combining polybutadiene backbone with pendant polyether chains in a comb-like architecture. This composite material structure integrates the hydrophobic polybutadiene backbone with hydrophilic polyether side chains, achieving high HLB values and improved miscibility while maintaining the structural integrity of the polymer.
3Shape
If epoxidized polybutadienes are reacted with lithium-polybutadiene compounds, then pendantly polyether-modified polybutadienes are formed, but the polybutadiene moiety becomes branched and the process requires organometallic compounds
Solution Approach 1:
The patent replaces complex organometallic catalysts with simple alkali metal hydroxides or double metal cyanide catalysts for the alkoxylation step. This substitution eliminates the need for specialized handling equipment and complex process controls required for organometallic compounds, thereby reducing device complexity and process complexity while achieving the same chemical transformation.
Solution Approach 2:
The patent changes the catalyst system from organometallic compounds to alkali metal hydroxides or double metal cyanide catalysts, and simultaneously changes the substrate from OH-terminated polybutadienes to pendantly hydroxy-functional polybutadienes. These parameter changes work together to produce linear polybutadiene backbones with pendant polyether chains, avoiding branching while simplifying the overall process.
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 allows for the production of polyether-modified polybutadienes with improved performance as adhesion promoters and defoamers, offering a broader range of chemical structures and industrial feasibility by avoiding the use of sensitive organometallic compounds and achieving higher HLB values and linear structures.
Implementation Method 1
The process involves the direct alkoxylation of pendantly hydroxy-functional polybutadienes with alkylene oxides, without using organometallic compounds, to produce polyether-modified polybutadienes with pendant polyether radicals
Implementation Method 2
further modifying these with cyclic anhydrides or lactones to form polyester-polyether-modified polybutadienes
Data Source
AI summary
Compounds are based on polyether-modified polybutadiene, where the polyether-modified polybutadiene contains repeat units selected from the divalent radicals:The radical B has at least one ester group.