Bimodal Sulfonated Polyarylenesulfone Membranes With Faster Polymerization
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Solution Overview
Problem
The production process for sulfonated polyarylenesulfone polymers is inefficient due to long reaction times and the challenges of isolating and recycling the polymers on a large scale, particularly when using high amounts of di-sulfonated monomers.
Innovation Solution
A sulfonated polyarylenesulfone polymer with a bimodal molecular weight distribution is developed, which improves membrane conductivity and simplifies the production process by reducing the need for extensive solvent rework and disposal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high amounts of di-sulfonated monomers are used to achieve desired membrane performance, then membrane conductivity is improved, but reaction time becomes extremely long and isolation becomes difficult
Solution Approach 1:
The patent segments the polymerization process into two distinct stages: a first polymerization step using a limited amount of di-sulfonated monomer (1-10 mol%) to form initial polymer chains, followed by a second polymerization step adding more di-sulfonated monomer (10-50 mol%) to increase conductivity. This segmentation allows the process to achieve high membrane conductivity while controlling reaction time by managing monomer addition rates across stages.
Solution Approach 2:
The patent applies preliminary action by first forming a base polymer structure with standard monomers before introducing di-sulfonated monomers. This preliminary polymerization creates a framework that can accommodate sulfonic acid groups without requiring extremely long reaction times from the outset, enabling progressive functionalization that achieves high conductivity with manageable reaction duration.
2Ease of manufacture
If conventional isolation methods (precipitation in isopropanol) are used, then polymer can be separated from reaction mixture, but huge volumes of solvent mixtures are created requiring rework or disposal
Solution Approach 1:
The patent changes the parameter of solvent selection from conventional isopropanol precipitation to using a different solvent system that enables easier polymer isolation. By selecting solvents with appropriate solubility characteristics for the sulfonated polyarylenesulfone, the process achieves effective polymer separation without generating huge volumes of solvent mixtures requiring extensive rework or disposal.
3Productivity
If direct sulfonation of polyarylenesulfone is performed, then sulfonated polymer can be obtained, but side reactions occur and degree of sulfonation cannot be controlled
Solution Approach 1:
Instead of direct sulfonation, the patent uses preliminary action by incorporating pre-sulfonated di-sulfonated monomer units (such as 3,3'-disulfonated 4,4'-dichlorodiphenyl sulfone) directly into the polymerization process. This approach allows controlled introduction of sulfonic acid groups during polymer chain formation, achieving precise control over the degree of sulfonation while maintaining high sulfonation efficiency without side reactions.
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 bimodal molecular weight distribution enhances the conductivity of membranes made from the sulfonated polyarylenesulfone polymer, while also streamlining the production process and reducing environmental impact.
Implementation Method 1
They need to be ion conductive and at the same time separate the gases hydrogen and oxygen
Implementation Method 2
separate the gases hydrogen and oxygen
Data Source
AI summary
The present invention relates a sulfonated polyarylenesulfone polymer (sP) having an at least bimodal molecular weight distribution, a process for the preparation of the sulfonated polyarylenesulfone polymer (sP), a membrane (M) comprising the sulfonated polyarylenesulfone polymer (sP), a process for the preparation of the membrane (M), and the membrane (M) obtained by said process.