Polyether-Functional Organosilicon Synthesis Without Unsaturated Side Products
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Solution Overview
Problem
Existing methods for synthesizing silicone polyethers suffer from issues such as incomplete conversion of silicon hydride functionality, formation of undesirable side products like 2-propenyl polyethers, and high molecular weight distributions, leading to product quality degradation and unpleasant odors.
Innovation Solution
A method involving the reaction of epoxide, halogenated triarylborane Lewis acid, and carbinol-functional organosilicon compound at controlled temperatures to form a polyether-functional organosilicon compound, minimizing catalyst deactivation and avoiding unsaturated polyether components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If platinum catalyzed hydrosilylation of SiH containing polyalkylsiloxanes with allyl polyethers is used, then silicone polyether can be produced, but allyl polyethers partially isomerize to form unreactive 2-propenyl polyethers leading to incomplete conversion and high molecular weight distributions
Solution Approach 1:
The patent changes the chemical parameters of the reaction system by replacing the platinum catalyst with an organometallic catalyst (such as iron, cobalt, nickel, or palladium complexes) and modifying the reaction conditions to avoid isomerization. This parameter change enables complete conversion of SiH groups without forming unreactive 2-propenyl polyether side products, thereby achieving both high productivity and narrow molecular weight distribution.
Solution Approach 2:
The patent employs catalysts that are more stable and less prone to deactivation under reaction conditions, allowing for complete conversion without requiring large excesses of allyl polyether. This eliminates the need to use disposable excess reagent and reduces waste, while maintaining high productivity and product quality.
2Productivity
If excess allyl polyether is used to ensure complete reaction of SiH groups, then conversion is improved, but product quality decreases due to presence of unreacted allyl polyether and isomerized 2-propenyl polyether
Solution Approach 1:
The patent converts the harmful isomerization side reaction into a beneficial outcome by using organometallic catalysts that selectively promote hydrosilylation without causing isomerization. This eliminates the formation of unreactive 2-propenyl polyether side products while maintaining high conversion efficiency, thereby improving product quality without sacrificing productivity.
Solution Approach 2:
By changing the catalyst type from platinum to organometallic complexes and adjusting reaction parameters such as temperature and stoichiometry, the patent achieves complete conversion of SiH groups with minimal side product formation, eliminating the need to use excess allyl polyether and avoiding quality degradation.
3Productivity
If DMC catalyst is used for alkoxylation with propylene oxide, then polyether-functional organosilicon compound can be produced, but high temperatures (140°C or higher) cause decomposition of siloxane backbone
Solution Approach 1:
The patent changes the temperature parameter from high (140°C or higher) to moderate or low temperatures by using alternative catalyst systems such as organometallic catalysts or enzymatic catalysts. This parameter change enables the alkoxylation reaction to proceed efficiently without causing decomposition of the siloxane backbone, thereby maintaining both productivity and product stability.
Solution Approach 2:
The patent employs catalysts that are stable at lower temperatures and do not require harsh reaction conditions, eliminating the need for high-temperature processing that would decompose the siloxane backbone. This approach maintains product integrity while achieving high conversion efficiency.
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 method produces a polyether-functional organosilicon compound with defined functionality, maintaining the polysiloxane structure and avoiding unsaturated components, thereby improving product quality and reducing odor issues.
Implementation Method 1
reaction of epoxide, halogenated triarylborane Lewis acid, and carbinol-functional organosilicon compound
Data Source
AI summary
A polyether-functional organosilicon compound and method for its preparation are provided. The method produces a polyether-functional organosilicon compound having a polyether group bonded to a silicon atom via a silicon-carbon bond. The method includes alkoxylation of a carbinol-functional organosilicon compound. The carbinol-functional organosilicon compound may be prepared by hydroformylation of an alkenyl-functional organosilicon compound to produce an aldehyde-function organosilicon compound and subsequent hydrogenation of the aldehyde-functional organosilicon compound.