1、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.

2、The epoxy resin system: function and role of curing agents

The performance of the new hardening in curing agent formulations with epoxy resin system is summarised in this review article. This hardening is intended for use in cementitious applications in industrial markets.

3、Curing Agent: Types & Process of Curing Agents for Epoxy Resin

Explore the main types of curing agents & various crosslinking methods which help to improve the polymerization process to select the right curing agent for coating formulation.

Curing Agents for Epoxy Resin (固化剂)

The epoxy resin compositions of Three Bond currently on the market are the Three Bond 2000 Series (base agent for epoxy resin), the Three Bond 2100 Series (curing agent for epoxy resin), and the Three Bond 2200 Series (one-part thermal cure epoxy compound resins).

Formulation of Epoxy Resin Adhesive Curing Agents

The performance of the new hardening in curing agent formulations with epoxy resin system is summarised in this review article. This hardening is intended for use in cementitious applications in industrial markets.

Epoxy Curing Agents – Part 1: Amines

Part 1 of this blog series has given a general introduction to amines, the largest class of curing agents for epoxy resins. We have a general understanding of how amines work and how to calculate the amount of amine required to cure an epoxy resin.

The epoxy resin system: function and role of curing agents

Depending on their chemical composition, curing agents can be cat-egorised as amine-type curing agents, alkali curing agents, anhydrides, or catalytic curing agents.

Synthesis and curing properties of fluorinated curing agent for epoxy

In the present work, we propose an entirely new biphenylamine-based curing agent (AFPCO) as an alternative to the commercially available curing agent 4,4`-diaminodiphenylmethane (DDM). Notably, AFPCO was synthesized from natural daidzein. The structure of the compound was determined by IR, 1 H NMR, 13 C NMR, and 19F NMR.

11 EPOXY RESINS AND CURING AGENTS

Epoxy resins are converted to a thermoset state by chemical reaction between the resin and a curing agent. Depending on the curing agent this reaction can take place at elevated temperatures or at room temperature. The cured resins are not soluble in solvents and cannot be melted by heating.

Formulation of Epoxy Prepregs, Synthesization Parameters, and Resin

The study indicated a systematic determination of each component in the resin formulation (resins, latent curing agent, accelerator, and latent curing additive) through the viscosity and curing steps.

Epoxy Resin Primary Curing Agent Formulations

Epoxy resin (Epoxy Resin) is a high-performance thermosetting resin widely used in electronics, automotive, aviation, construction, and other fields due to its excellent mechanical properties, electrical insulation, and adhesive characteristics. Primary curing agents are indispensable auxiliary materials in the curing process of epoxy resin. Their main function is to promote the cross-linking reaction between the resin and the curing agent, thereby accelerating the curing process and improving the mechanical and environmental resistance properties of the final product.

1. Functions of Primary Curing Agents

Primary curing agents play the following key roles in epoxy resin systems:

1. Promote Cross-Linking Reactions: Primary curing agents provide active functional groups that chemically react with epoxide groups in the epoxy resin, forming stable bonds to accelerate the curing process.

2. Adjust Curing Time: Different primary curing agents have varying activities. By adjusting their type and dosage, the curing time and degree of epoxy resin can be effectively controlled.

3. Improve Mechanical Properties: Primary curing agents enhance the toughness, strength, and hardness of epoxy resin, making it suitable for manufacturing structural components and composite materials.

4. Enhance Adhesion: They strengthen the adhesion between epoxy resin and substrates, improving the overall performance of the product.

5. Reduce Curing Temperature: Certain primary curing agents enable curing at lower temperatures, contributing to energy savings.

2. Classification of Primary Curing Agents

Primary curing agents are classified into the following categories based on their chemical composition and function:

1. Amine-Based Curing Agents: Examples include imidazole and piperazine, which provide active hydrogen atoms to form stable ring compounds through addition reactions with epoxide groups.

2. Acid-Based Curing Agents: Examples include phosphoric acid and sulfuric acid, which act as proton donors to catalyze acid-driven cross-linking reactions.

3. Alcohol-Based Curing Agents: Examples include methanol and ethanol, which provide hydroxyl groups for etherification reactions with epoxide groups, forming stable ester bonds.

4. Phenol-Based Curing Agents: Examples include phenol and cresol, which offer phenolic hydroxides for condensation reactions with epoxide groups, forming stable ether bonds.

5. Ketone-Based Curing Agents: Examples include acetone and acetonitrile, which provide carbonyl groups for acylation reactions with epoxide groups, forming stable ketone bonds.

3. Selection of Primary Curing Agents

Choosing the appropriate primary curing agent is critical for optimizing epoxy resin performance. Key considerations include:

1. Application Requirements: Select curing agents based on the intended use and desired properties. For example, imidazole or amine-based agents are suitable for fast curing, while acid- or phenol-based agents are better for high-strength applications. Ketone-based agents are ideal for low-temperature curing.

2. Cost Factors: Evaluate the cost and availability of curing agents, prioritizing cost-effective and environmentally friendly options with low toxicity.

3. Compatibility: Ensure compatibility between the curing agent and epoxy resin to maintain stable product performance. Compatibility can be verified experimentally.

4. Storage Stability: Choose curing agents with good storage stability to prevent degradation or deactivation over time. Consult literature or suppliers for storage guidelines.

4. Practical Application Examples

For a specific epoxy resin model, the application of primary curing agents involves:

1. Preparation: Mix the epoxy resin with an appropriate solvent, then add the primary curing agent uniformly.

2. Curing Conditions: Apply the mixture to a mold and cure in an oven. Adjust curing temperature and duration based on application requirements.

3. Performance Testing: After curing, test mechanical properties, thermal stability, and environmental resistance. Evaluate the impact of the curing agent on resin performance.

4. Optimization: Refine the type, dosage, and ratio of curing agents based on testing results and practical needs to enhance overall performance.

Primary curing agents are essential for promoting cross-linking reactions in epoxy resin systems, accelerating curing, and improving mechanical and environmental resistance. The selection of curing agents significantly impacts resin performance. In practice, curing agents should be chosen based on specific application scenarios and optimized through experimentation. Continued refinement can further expand the potential applications and performance of epoxy resin.