Segmented Sulfonated Block Copolymers for Ion Conductivity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sulfonated block copolymers face challenges in achieving optimal dimensional stability and ion transport while maintaining low water uptake, which is crucial for applications like electrically driven water separation and osmosis processes.

Innovation Solution

Modified sulfonated block copolymers with specific polymer end blocks and interior blocks, incorporating sulfonation susceptible monomer units, are developed to enhance dimensional stability and ion conductivity, featuring a configuration of A-B-A or A-B-A-B-A, where A blocks are resistant to sulfonation and B blocks are susceptible, with controlled sulfonation levels and functional groups.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sulfonic acid or sulfonate functional groups are added to enhance ion transport, then ion conductivity is improved, but water uptake increases and dimensional stability deteriorates

Engineering Contradiction:
Improveion conductivityVSAvoiddimensional stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The polymer is divided into distinct functional blocks: A blocks (sulfonation-resistant) and B blocks (sulfonation-susceptible). This segmentation allows concentrated ionic functionality in B blocks for high ion conductivity while A blocks maintain dimensional stability and resist water uptake, resolving the contradiction between ion transport and structural stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the polymer exhibit different properties: A blocks provide dimensional stability and sulfonation resistance, while B blocks provide ion conductivity through controlled sulfonation. This local differentiation allows the material to simultaneously achieve high ion conductivity in B blocks while maintaining overall dimensional stability through A blocks.

Inventive Principle:
Principle #3Local quality

2Reliability

If sulfonation level is increased to improve ion conductivity, then ion transport is enhanced, but water uptake increases

Engineering Contradiction:
Improveion transportVSAvoidwater uptake
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The polymer chains are segmented into A and B blocks with distinct functions. B blocks are sulfonated to high levels (10-100 mol%) for excellent ion transport, while A blocks remain sulfonation-resistant and hydrophobic, creating a segmented structure where ionic clusters are isolated within B blocks surrounded by water-resistant A blocks, thus enhancing ion transport while limiting water uptake.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

High sulfonation density is localized to B blocks where it is needed for ion transport, while A blocks maintain low sulfonation levels to resist water uptake. This local quality differentiation allows the material to achieve high ion conductivity in specific regions without compromising overall water resistance.

Inventive Principle:
Principle #3Local quality

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 modified sulfonated block copolymers exhibit improved dimensional stability, high ion conductivity, and low water uptake, making them suitable for various applications including electrically driven water separation and osmosis processes.

Implementation Method 1

selective ion transport

Methodology Applied
Scientific EffectIon transport: Ion Repulsion/Attraction

Implementation Method 2

water transport

Methodology Applied
Scientific EffectWater transport: Osmosis

Data Source

PatentEP2731998B1Modified sulfonated block copolymers and the preparation thereof
Publication Date: 2016.05.18 KRATON POLYMERS US LLC
  • EP2731998B1 patent drawingFigure 1~2
  • EP2731998B1 patent drawingFigure 3~4
  • EP2731998B1 patent drawingFigure 5~6

AI summary

Described herein are modified sulfonated block copolymers which comprise at least two polymer end blocks A and at least one polymer interior block B, wherein each A block contains essentially no sulfonic acid or sulfonate functional groups and each B block comprises sulfonation susceptible monomer units and, based on the number of the sulfonation susceptible monomer units, from about 10 to about 100 mol% of a functional group of formula (I) -SO2-NR1R2 or of a salt thereof, methods of making them as well as methods of using them, e.g., as membrane materials for electrically or osmotically driven applications.