Vegetable Oil Polyol Synthesis via Transesterification and Thiolation
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Solution Overview
Problem
Current methods for synthesizing polyols from vegetable oils result in materials with ill-defined structures and functionalities, leading to uncontrollable reaction sites and the formation of numerous by-products, which complicates the production of functional precursors for polymers.
Innovation Solution
A two-step method involving transesterification and thiolation of mono- or di-esters of vegetable oil, using specific catalysts and conditions to produce well-defined, bi-functional polyols with primary hydroxyl functions, allowing for controlled functionality and reproducible polymer properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If direct oxidation of double bonds is used to introduce hydroxyl groups, then polyols can be obtained with low cost and one-step synthesis, but the oxidation control is unsatisfactory and numerous by-products are formed
Solution Approach 1:
The patent segments the synthesis process into two distinct steps: first epoxidation of double bonds to form epoxy groups, then ring-opening of epoxy groups to introduce hydroxyl groups. This segmentation allows each step to be independently controlled, improving oxidation control and reducing by-products while maintaining the benefits of the overall process
Solution Approach 2:
The patent introduces epoxy groups as an intermediary functional group between the double bonds and the final hydroxyl groups. This intermediary step (epoxidation) provides a controlled pathway that avoids the uncontrolled direct oxidation issues, allowing for better product purity and control over the introduction of hydroxyl functionality
2Adaptability or versatility
If triglycerides are used as base materials with multiple fatty acid types, then vegetable oil polyols can be synthesized with natural origin benefits, but the complex mixture leads to ill-defined structures and functionalities
Solution Approach 1:
The patent applies local quality by allowing different fatty acid chains within the triglyceride mixture to undergo the same epoxidation and ring-opening reactions, resulting in a polyol where each molecule has well-defined local functionalities (epoxy and hydroxyl groups) despite the diversity of the hydrocarbon chains. This maintains the natural origin benefits while achieving controlled functionality
Solution Approach 2:
The patent changes the chemical parameters of the triglyceride molecules by systematically introducing epoxy groups at the double bond positions and then converting them to hydroxyl groups. This parameter change (functional group transformation) applies uniformly across the complex mixture, resulting in polyols with well-defined functionalities despite the diversity of starting materials
3Productivity
If high temperature is used to migrate double bonds to form conjugate sites, then condensation reactions can be facilitated, but the reaction conditions become harsh and control is reduced
Solution Approach 1:
The patent changes the reaction parameters from high-temperature thermal processes to milder conditions using organometallic catalysts. This allows the same condensation reactions to proceed at lower temperatures with better control and selectivity, maintaining productivity while improving manufacturing precision
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 enables the production of polyols with well-defined structures and controlled functionalities, improving the properties and consistency of resulting polymers, such as polyurethanes, and expanding their applications in rigid foams, electrical insulation, coatings, and adhesives.
Implementation Method 1
b) a thiolation step of the compound of above-mentioned formula (IV) to obtain a compound of formula (I) such as defined above, the thiolation step being a reaction step of the compound of above-mentioned formula (IV) with a thiol of formula HS-A3-OH
Implementation Method 2
a) a transesterification step of a compound of the following formula (II′) with a diol of the following formula (III)
Data Source
AI summary
A method for preparing a polyol having the following general formula (I): the method including a step of transesterification followed by a step of thiolation. The present invention also relates to polyols with the formula (T) such as those defined above.