1、Organic
Herein, the preparation and performance of processable luminescent EP vitrimers using carboxylic acid CDs as curing agents to cure epoxy monomer (DER332) and transesterification agent to construct dynamic exchangeable bonds in the crosslinking network were proposed for the first time in this work.
2、Enhancement of Biobased Epoxy Through the Curing and Thermal Stability
Carboxylic acids, salicylic, maleic, and citric acids, all with a purity of 98%, were used as curing agents and were acquired from Sigma Aldrich (São Paulo, Brazil).
3、New biobased carboxylic acid hardeners for epoxy resins
Soybean oil was modified into a novel biobased polyacid hardener by thiol-ene coupling with thioglycolic acid. The structure of the initial soybean oil and polyacid triglyceride was carefully analyzed using 1 H NMR and titration.
4、Novel phosphorus/nitrogen/boron
A carboxylic acid containing P/N/B was prepared and used as flame-retardant co-curing agent for anhydride-cured EP.
5、Synthesis of Biobased Flame
HCPVC was used as a curing agent to employ in wood epoxy coating. The optimum curing condition of epoxy resin (DY-E44) with HCPVC and its apparent activation energy were determined by differential scanning calorimetry (DSC), and the results showed that it was suitable for utilizing in wood.
Effect of Dicarboxylic Acids’ Aliphatic Chain on the Curing of
The use of carboxylic acids as hardeners for biobased resins from epoxidized oils is also discussed as a promising development in this field. However, there is a lack of research in this area, and finding the right combination of carboxylic acids and epoxidized oils remains a challenge.
Theoretical studies of mechanisms of epoxy curing systems
four main curing reactions, epoxy-amine, epoxy-phenol, epoxy-acid and epoxy-anhydride, at the molecular-level using B3LYP density functional theory. The strength of these mechanistic models is their ability to extrapolate to different reactions that use a particular epoxy resin, a particular curing agent and/or a particular catalyst.
Novel phosphorus/nitrogen/boron
It is a great challenge to develop a high-efficiency reactive flame retardant, applied to anhydride-cured epoxy resin (EP) system, simultaneously possessing good compatibility with matrix and mechanical reinforcement.
Curing reactions of epoxy powder coatings in perspectives of chemical
The properties of the cured products of epoxy powder coatings are dominated by the curing systems. This review discusses the types, reaction principles, characteristics of curing agents and accelerators that participate in the curing reaction with different epoxy resins.
Influence of different composite curing agents on the rapid curing
In particular, effective formulations are designed for mixing fast and slow curing agents, studying their effects on the curing behavior, curing quality, and mechanical properties of epoxy resins and elucidating their influence mechanisms.
In modern industry, epoxy materials are widely used in various fields due to their excellent mechanical properties, chemical resistance, and electrical insulation. The curing process of epoxy materials is a critical step in realizing these characteristics. During this process, the role of epoxy curing agents is indispensable. Epoxy curing agents are chemicals specifically designed to promote the curing of epoxy resins. They react with hydroxyl groups in the epoxy resin to form stable chemical bonds, thereby accelerating and enhancing curing efficiency. In this process, carboxylic acids, as a crucial component of epoxy curing agents, play a vital role.
Carboxylic acids, as the name suggests, are organic compounds containing a carboxyl group (-COOH). This structure endows carboxylic acids with unique chemical properties, enabling them to perform exceptionally well in many chemical reactions. For epoxy curing agents, the functions of carboxylic acids mainly manifest in the following aspects:
- Promoting Curing: Carboxylic acids react with hydroxyl groups in epoxy resins to form stable ester bonds, a process known as polymerization. In this way, carboxylic acids not only accelerate the curing process but also improve the physical and chemical properties of the cured material.
- Improving Adhesion: Carboxylic acids can reduce the surface energy between epoxy resins and substrates, thereby enhancing adhesion between them. This is particularly important for applications requiring high-strength bonding, such as electronic packaging, automotive manufacturing, and other fields.
- Regulating Viscosity: Carboxylic acids can partially lower the viscosity of epoxy resins, making the material easier to process and apply. This is significant for automated production lines and large-scale manufacturing.
- Providing Crosslinking Density: During the curing process, carboxylic acids not only participate in reactions but also promote crosslinking reactions. This helps improve the mechanical properties and thermal stability of the material.
- Controlling Curing Time: The type and concentration of carboxylic acids directly affect curing speed. By selecting appropriate carboxylic acids, curing time can be effectively controlled to meet the needs of different application scenarios.
the role of carboxylic acids in epoxy curing agents is not without challenges. First, the cost of carboxylic acids is relatively high, which may increase the overall cost of the curing agent. Second, the volatility of carboxylic acids could pose environmental and health risks to operators. Additionally, certain specific applications may require specialized carboxylic acids to achieve optimal results, adding complexity to selection and use.
To address these challenges, researchers and companies are continuously exploring new solutions. For example, improving production processes to reduce the amount of carboxylic acids required or developing alternative products with similar performance at lower costs. For specific applications, optimizing curing effects by adjusting the type and concentration of carboxylic acids can also meet diverse needs.
Looking ahead, with advancements in science and technology and growing environmental awareness, we have reason to believe that the application of carboxylic acids in epoxy curing agents will be further optimized and expanded. By developing more efficient, cost-effective, and environmentally friendly carboxylic acids for epoxy curing agents, broader opportunities will be created for the application and development of epoxy materials.
as a key component of epoxy curing agents, carboxylic acids not only play a critical role in the curing process but also contribute to enhancing the performance of epoxy materials in many other ways. In future developments, we look forward to more innovations and breakthroughs that will enable epoxy materials to better serve social and economic progress.
