Reversible Ionic Crosslinking in Polymers via Redox Triggers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polymer technologies face challenges in achieving non-thermal reversible crosslinking for mechanical tunability, as existing methods are either heat-dependent, slow, or require complex synthesis, limiting their applicability in large parts and environmental responsiveness.
Innovation Solution
A polymer composition comprising ionic species, a redox reagent, and a reversible crosslinking agent that changes oxidation states in response to naturally occurring stimuli like light, allowing for ionic crosslinking and decrosslinking without heat, enabling mechanical adjustability and reworkability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If thermally triggered Diels-Alder chemistry is used for reversible crosslinking, then the polymer can be remolded and reshaped, but uniform heating is difficult to achieve for large parts and the response is slow and gradual
Solution Approach 1:
The patent replaces thermal triggering with mechanical stress triggering. The polymer network uses mechanoresponsive elements that respond to applied mechanical stress rather than heat, enabling faster and more uniform response across large parts without the slow thermal diffusion limitations of Diels-Alder chemistry
Solution Approach 2:
The patent changes the triggering parameter from temperature to mechanical stress. By using stress-triggered bond breaking and formation, the system achieves rapid response times and uniform activation across the entire polymer network, eliminating the gradual response inherent in thermal processes
2Adaptability or versatility
If reversible crosslinking is introduced into a polymer network, then the material can be remolded and shaped, but the material becomes vulnerable to creep under stress
Solution Approach 1:
The patent creates a dynamic polymer network where crosslinks can reversibly break and reform in response to applied stress. The mechanoresponsive elements allow the network to adapt its structure under load, breaking temporary crosslinks to allow chain slippage (preventing permanent deformation) and reforming them when stress is removed, thus resisting creep while maintaining remoldability
Solution Approach 2:
The patent combines covalent crosslinks with non-covalent mechanoresponsive crosslinks in a composite network structure. The covalent bonds provide permanent structural integrity and creep resistance, while the reversible non-covalent bonds enable remoldability and stress-responsive behavior
3Adaptability or versatility
If supramolecular-based polymer systems are used for chemoresponsive materials, then the materials can be altered by components that compete with existing covalent bonds, but these systems are difficult and expensive to synthesize
Solution Approach 1:
The patent extracts the chemoresponsive functionality from complex supramolecular systems and implements it through simpler mechanoresponsive non-covalent crosslinks. This approach achieves chemical alterability through competition with covalent bonds using straightforward polymer chemistry rather than difficult supramolecular synthesis
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 polymers to reversibly change mechanical properties in response to environmental stimuli, enhancing their reworkability and adaptability, suitable for various applications including coatings and polymer parts without the need for heat-induced processes.
Implementation Method 1
a redox reagent, and a reversible crosslinking agent capable of changing from a first oxidation state to a second oxidation state when in the presence of the redox reagent
Implementation Method 2
a first polymer containing a plurality of ionic species disposed along a chain backbone of the first polymer
Data Source
AI summary
This invention provides compositions and methods for reversible ionic crosslinking in polymers, providing tunability of polymer mechanical properties. Some variations provide a polymer composition comprising: a polymer containing a plurality of ionic species disposed along the chain backbone of the polymer, wherein the plurality of ionic species has an ionic charge polarity that is negative or positive; a redox reagent; and a reversible crosslinking agent capable of changing from a first oxidation state to a second oxidation state when in the presence of the redox reagent. The different oxidation states are associated with different coordination numbers between the reversible crosslinking agent and the ionic species contained in the polymer. This difference provides reversible ionic crosslinking. The polymer may be selected from polyurethanes (including segmented and non-segmented polyurethanes), polyacrylates, or polyamides, for example. These polymers are useful for many commercial applications, including coatings and polymer parts.