Fluorinated Ion Exchange Polymer Liquid Compositions
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Solution Overview
Problem
Existing liquid compositions of fluorinated ion exchange polymers, particularly those used in membrane production, face challenges with high viscosity and the use of alcohol-based solvents, which can cause side reactions and safety hazards, and are unsuitable for preparing composite membranes due to surface wetting issues and the need for high pressures and temperatures.
Innovation Solution
A liquid composition of a fluorinated ion exchange polymer in aprotic organic solvents, comprising 40 to 94 mol% recurring units from chlorofluoroolefins and 6 to 60 mol% recurring units from functional monomers, allowing for the preparation of ion exchange membranes under mild conditions, with the polymer being soluble in aprotic organic solvents and suitable for proton exchange membranes without additional activation treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If alcohol-based liquid compositions are used for fluorinated ion exchange polymers, then the polymer can be dissolved and processed, but the composition exhibits high viscosity and causes safety hazards and side reactions
Solution Approach 1:
The patent changes the chemical composition parameters by replacing alcohol-based solvents with a specific water-organic solvent mixture (5-50% water, 50-95% organic solvent). This parameter change resolves the contradiction by eliminating the harmful effects of alcohols while maintaining polymer solubility and processing capability, achieving low viscosity and safety without sacrificing ease of manufacture
Solution Approach 2:
The patent uses water as a partial replacement for organic solvents, leveraging water's safety, low cost, and non-flammability. This substitution eliminates safety hazards and reduces viscosity while maintaining adequate polymer dissolution capability, resolving the contradiction between ease of manufacture and harmful factors
2Ease of manufacture
If alcohol-based liquid compositions are used, then polymer solutions can be prepared, but they are unsuitable for preparing composite membranes due to surface wetting issues
Solution Approach 1:
The patent modifies the solvent composition parameters by using a water-organic solvent system with specific proportions (5-50% water, 50-95% organic solvent). This parameter change improves surface wetting properties compared to alcohol-based systems, enabling the polymer solution to be suitable for composite membrane preparation while maintaining ease of manufacture
3Ease of manufacture
If conventional dissolution processes are used for fluorinated ion exchange polymers, then polymer solutions can be obtained, but high pressures and temperatures are required
Solution Approach 1:
The patent changes the solvent system parameters from conventional high-temperature solvents to a water-organic solvent mixture that enables polymer dissolution at room temperature or mild heating. This parameter change resolves the contradiction by maintaining polymer solution obtainment capability while eliminating the requirement for high pressures and temperatures
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 solution enables the production of ion exchange membranes with good ion conductivity, low gas permeability, and high stability for fuel cell applications, overcoming the limitations of viscosity and solvent-related issues in existing technologies.
Implementation Method 1
liquid compositions of a fluorinated ion exchange polymer in aprotic organic solvents... the polymer being soluble in aprotic organic solvents
Data Source
AI summary
A liquid composition comprising at least one aprotic organic solvent and at least one fluorinated ion exchange polymer which consists of recurring units derived from a chlorofluoroolefin of formula CF2=CCIY, wherein Y is F or CI, and from at least one fluorinated functional monomer selected among those of formula CF2 =CF-O-(CF2CF(CF3)O)m-(CF2)nSO2X, wherein m is an integer equal to 0 or 1, n is an integer from 0 to 10 and X is chosen among halogens (CI, F, Br, I), -O-M+, wherein M+ is a cation selected among H+, NH4 +, K+, Li+, Na+, or mixtures thereof is disclosed. The liquid composition is suitable for the preparation of ion exchange membranes, in particular composite membranes, for use in fuel cell applications.