Disulfide Crosslinked Polyester Resin for Self-Healing Adhesion
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Solution Overview
Problem
Existing crosslinked polyester resins are difficult to recycle and reuse due to their heat-resistant and solvent-resistant properties, and lack self-healing and moldability, as well as effective adhesion to substrates like PET and polyimide films.
Innovation Solution
A crosslinked polyester resin with disulfide bonds is developed, allowing for dynamic covalent crosslinking that enables self-healing and moldability, with a relaxation modulus adjustment through ester and disulfide bond exchanges, and adhesion to substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a crosslinked polyester resin is used to achieve high heat resistance and chemical resistance, then the resin exhibits high strength and stability, but it becomes difficult to melt by heat or dissolve in solvents, making recycling and repeated use challenging
Solution Approach 1:
The patent introduces dynamic covalent bonds (disulfide bonds and ester bonds) into the crosslinked polyester resin network. These bonds can undergo reversible exchange reactions under specific conditions (heat, catalyst), allowing the resin to transition from a rigid crosslinked structure to a more flexible state that enables melting and reshaping, thus achieving recyclability while maintaining high temperature stability during service
Solution Approach 2:
The patent utilizes bond exchange reactions that are activated by changing parameters such as temperature and catalyst presence. At service temperatures, the crosslinked structure provides high strength and heat resistance. At processing temperatures with catalyst activation, the bond exchange reactions enable the resin to soften and become processable, allowing for recycling and remolding
2Strength
If a thermosetting resin is used to achieve high adhesion and durability, then the resin provides strong bonding, but it lacks self-healing properties and moldability
Solution Approach 1:
The patent incorporates dynamic bond exchange mechanisms that allow the resin to adapt its structure in response to environmental conditions. The disulfide bond exchange and ester bond exchange reactions enable the resin to flow and reconfigure at elevated temperatures, providing moldability, while maintaining strong adhesion at service temperatures through the crosslinked network structure
Solution Approach 2:
The patent exploits temperature-induced phase transitions and bond exchange reactions to enable self-healing and moldability. When heated to the activation temperature for bond exchange, the resin transitions from a rigid crosslinked state to a softer, more mobile state that allows for reshaping and healing of defects, then returns to the crosslinked state upon cooling, restoring strength and adhesion
3Ease of manufacture
If the activation temperature for bond exchange is lowered to enable self-healing and moldability, then the resin becomes processable at lower temperatures, but the strength and stability at room temperature may be compromised
Solution Approach 1:
The patent creates a composite crosslinked network containing both disulfide bonds and ester bonds, each contributing different properties. The disulfide bonds provide reversible crosslinking that enables self-healing and moldability at moderate temperatures, while the ester bonds contribute to the overall structural integrity and room temperature strength, creating a synergistic effect that balances processability and mechanical performance
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 resin exhibits high strength at room temperature, softens at lower temperatures for self-healing, and adjusts bond exchange temperatures through disulfide bond ratios, facilitating recyclability and effective bonding.
Implementation Method 1
a resin that possesses two types of reactive sites in one polymer chain, one for an ester bond exchange and the other for a disulfide exchange reaction
Implementation Method 2
a resin that possesses two types of reactive sites in one polymer chain, one for an ester bond exchange and the other for a disulfide exchange reaction
Data Source
AI summary
An object of the present invention is to provide a crosslinked polyester resin that exhibits high self-healing properties, high molding processability while exhibiting high adhesion to resin substrates such as a PET film and a polyimide film. A crosslinked polyester resin having a disulfide bond, obtained by crosslinking a polyester (A) having a carboxy group with an epoxy compound (B). A paint, a coating agent, and an adhesive containing the crosslinked polyester resin. An assembly including a layer containing the crosslinked polyester resin and adherend.