Inert Solvent Process for Polyether-Polyester Block Copolymers
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Solution Overview
Problem
Conventional processes for producing polyether-polyester block copolymers require excessive aliphatic diols as solvents, which are difficult to remove due to high boiling points and covalent bonding, leading to lengthy reaction times and inefficient solvent control.
Innovation Solution
A process involving a transesterification reaction of di(C1-C4)alkyl esters of aromatic dicarboxylic acids with aliphatic diols or polyols in an inert solvent, followed by polycondensation with polyethers, allowing for the use of reduced aliphatic diol amounts and easier removal of alcohol by-products through refluxing inert solvents, thereby shortening reaction times and eliminating the need for high vacuum and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If excessive aliphatic diol is used as solvent to prevent sublimation of aromatic dicarboxylic acid dialkylester, then sublimation is prevented, but the reaction time becomes very long and high vacuum/temperature is required for solvent removal
Solution Approach 1:
The patent uses an inert solvent as an intermediary substance to dissolve both the aromatic dicarboxylic acid dialkylester and aliphatic diol, replacing the conventional approach of using excessive diol as solvent. This inert solvent mediates the reaction without requiring removal afterward, thus preventing sublimation while avoiding the time-consuming solvent removal step. The inert solvent acts as a temporary carrier that facilitates the reaction then can be easily eliminated.
Solution Approach 2:
The patent changes the physical state and composition parameters of the reaction system by introducing an inert solvent with appropriate boiling point and solubility characteristics. This parameter change allows the aromatic dicarboxylic acid dialkylester to remain in solution without sublimation, while the inert solvent can be easily removed by simple evaporation rather than requiring prolonged high vacuum and temperature conditions.
2Stability of the object's composition
If excessive aliphatic diol is used as solvent, then sublimation is prevented, but high temperature and very low pressure are required for solvent removal
Solution Approach 1:
The inert solvent serves as an intermediary that can be easily removed by simple evaporation at moderate conditions, replacing the excessive diol that requires harsh removal conditions. The inert solvent's physical properties (lower boiling point, no covalent bonding to products) make it an ideal temporary medium that facilitates the reaction then can be eliminated without requiring high temperature and very low pressure.
Solution Approach 2:
The inert solvent functions as a disposable medium that is introduced for the reaction and then easily removed without needing recovery or complex processing. Unlike the excessive diol that must be painstakingly removed under harsh conditions, the inert solvent can be simply evaporated, representing a cheap and easy-to-eliminate substance that serves its purpose and is then discarded.
3Stability of the object's composition
If alkylene glycol is used as solvent, then sublimation is prevented, but the amount of solvent to be removed is difficult to control
Solution Approach 1:
The inert solvent provides a controlled and predictable medium for the reaction. Its inert nature and well-defined physical properties allow for precise control of the reaction conditions and solvent amount. Unlike alkylene glycol where solvent control is difficult, the inert solvent's lack of reactivity and consistent behavior make the amount of solvent to be removed easily controllable and predictable.
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 approach prevents sublimation of di(C1-C4)alkyl esters, reduces reaction time, and minimizes the need for high-temperature, low-pressure conditions, enabling more controlled and efficient production of polyether-polyester block copolymers.
Implementation Method 1
transesterification reaction of at least one di(C1-C4)alkyl ester of aromatic dicarboxylic acid and at least one aliphatic diol or aliphatic polyol in an inert solvent, wherein the inert solvent has a boiling point higher than the boiling point of the alcohol by-product of the transesterification reaction
Implementation Method 2
allowing for the use of reduced aliphatic diol amounts and easier removal of alcohol by-products through refluxing inert solvents
Implementation Method 3
easier removal of alcohol by-products through refluxing inert solvents
Data Source
AI summary
The present invention discloses a process for producing a polyether-polyester block copolymer with a di(C 1-C 4)alkyl ester of aromatic dicarboxylic acid, an aliphatic diol or aliphatic polyol and a polyether having at least one terminal hydroxyl group in an inert solvent. In the present invention, the inert solvent 5 is used to prevent the di(C 1-C 4)alkyl ester of aromatic dicarboxylic acid from sublimation instead of excessive polyol, such that the subsequent removal of excessive polyol under high temperature and high vacuum is avoided.