Aqueous Fluoropolymer Composition Purification by Membrane Separation
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Solution Overview
Problem
Existing methods for producing fluoropolymers with sulfonic acid or carboxyl groups are inefficient in removing low molecular weight substances, leading to compositions with undesirably high levels of these impurities.
Innovation Solution
A method involving ultrafiltration, microfiltration, or dialysis membrane treatment is employed to remove low molecular weight substances from compositions containing fluoropolymers, utilizing a polymer with specific structural units and ionic groups, thereby reducing impurities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional production methods are used for fluoropolymers with sulfonic acid or carboxyl groups, then the polymer can be produced, but low molecular weight substances remain at high levels in the composition
Solution Approach 1:
The patent applies extraction by removing low molecular weight substances from the fluoropolymer composition through ultrafiltration and dialysis membrane treatment. These membrane-based separation processes selectively extract impurities while retaining the desired fluoropolymer, thereby reducing the quantity of low molecular weight substances and improving composition purity.
Solution Approach 2:
The patent uses ultrafiltration membranes and dialysis membranes as intermediary substances to facilitate the removal of low molecular weight impurities. These membranes act as mediators that enable selective separation based on molecular size, allowing the purification process to occur efficiently without direct chemical modification of the polymer.
2Manufacturing precision
If ultrafiltration or dialysis membrane treatment is applied to remove low molecular weight substances, then composition purity improves, but additional processing steps are required
Solution Approach 1:
The patent extracts low molecular weight substances using ultrafiltration and dialysis membranes, which are well-established separation technologies. By leveraging these proven methods rather than developing new complex systems, the patent achieves effective purification while maintaining reasonable process simplicity.
Solution Approach 2:
The patent optimizes parameters such as molecular weight cutoff selection, membrane type, treatment conditions (temperature, pressure, time), and concentration ranges to achieve effective purification. By carefully adjusting these parameters, the process achieves high purity with minimal complexity, balancing separation efficiency with operational simplicity.
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 effectively reduces low molecular weight substances to low levels, resulting in a more pure and efficient composition suitable for applications such as electrolyte films and chemical sensors.
Implementation Method 1
performing ultrafiltration, microfiltration, dialysis membrane treatment, or a combination thereof on a composition comprising water and a fluoropolymer
Implementation Method 2
performing ultrafiltration, microfiltration, dialysis membrane treatment, or a combination thereof on a composition comprising water and a fluoropolymer
Data Source
AI summary
A method for producing a composition including a step A of performing ultrafiltration, microfiltration, dialysis membrane treatment, or a combination thereof on a composition containing water and a fluoropolymer. The fluoropolymer is a polymer having a structural unit M3 derived from a monomer represented by general formula (1):CX2═CY(—CZ2—O—Rf-A) (1)where X is the same or different and is —H or —F; Y is —H, —F, an alkyl group, or a fluorine-containing alkyl group; Z is the same or different and is —H, —F, an alkyl group, or a fluoroalkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and having an ether bond; and A is —COOM, —SO3M, —OSO3M, or —C(CF3)2OM, wherein M is as defined herein; provided that at least one of X, Y, and Z includes a fluorine atom.