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

Epoxy resins are frequently used in electrical devices, castings, packaging, adhesive, corrosion resistance, and dip coating. In the presence of curing agents, epoxy resins become rigid and infusible. Eco-friendliness and mechanical functionality have emerged as vulcanization properties.

3、The Impact of the Acidic Environment on the Mechanical Properties of

The aim of this work was to determine the impact of the acidic environment on the mechanical properties of two epoxy compounds in different conditions. The samples were made from the epoxy compounds composed of the epoxy resin (based on Bisphenol ...

4、Effect of Curing Agent Type on Curing Reaction Kinetics of Epoxy Resin

In this paper, low molecular weight polyamides, aromatic amines and anhydrides were selected as three kinds of curing agents and their isothermal viscosity-time properties were studied to...

Effect of the Structure of Epoxy Monomers and Curing Agents: Toward

The effect of the structures of epoxy monomers and curing agents regarding the intrinsic thermal conductivity, dielectric proper-ties, insulation performance, thermomechanical properties, thermal stability, and hydrophobicity of the prepared epoxy resins was systematically explored.

Selection and Application of Acidic Epoxy Curing Agents

Acidic curing agents, with their distinct chemical characteristics, play a pivotal role among various curing agents. This article explores how to correctly select and use acidic epoxy curing agents.

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.

A critical review of dynamic bonds containing curing agents for epoxy

Investigated the mechanical, thermomechanical, thermal, and recycling properties of the epoxy thermosets cured by developed curing agents. Addressed the challenges, opportunities and emerging trends in the field.

Epoxy Curing Agents: A Comprehensive Understanding of Their

Explore the basic knowledge of epoxy curing agents, including their classification, working principle, wide application in construction, electronics, automotive and other industries, as well as market trends and the latest developments of environmentally friendly products.

Epoxy Curing Agents

This chapter focuses on epoxy curing agents, also known as curatives, which include crosslinkers and catalysts.

Interactions Between Epoxy Curing Agents and Acidic Gases

In modern industrial and construction industries, epoxy resins are widely used due to their excellent mechanical properties, chemical resistance, and electrical insulation. challenges may arise during the curing process of epoxy, one of which is the reaction with acidic gases in the environment. Acidic gases such as sulfur dioxide (SO₂), hydrogen sulfide (H₂S), and ammonia (NH₃) can impact the performance of epoxy coatings and even lead to coating failure. Understanding the interactions between epoxy curing agents and acidic gases is critical to ensuring coating quality.

Overview of Epoxy Curing Agents

Epoxy curing agents are substances used to promote the curing of epoxy resins. They typically contain one or more reactive functional groups, such as hydroxyl (-OH), amino (-NH₂), or carboxyl (-COOH) groups. These functional groups react chemically with the epoxide groups in epoxy resins to form stable cross-linked structures, significantly enhancing the material’s mechanical strength and chemical resistance.

Impact of Acidic Gases

When epoxy coatings are exposed to environments containing acidic gases, these gases can chemically react with the active functional groups in the curing agents. Specifically, acidic gases like SO₂, H₂S, and NH₃ can interact with hydroxyl, amino, or carboxyl groups in epoxy curing agents. Such reactions may lead to degradation of the curing agent, reduced cross-linking density, or diminished coating performance.

Reaction Mechanisms

1. Hydroxyl Group Reactions:

   • Acidic gases such as SO₂ and H₂S can react with hydroxyl groups in epoxy curing agents, forming sulfate or sulfite esters. These compounds may further convert into more stable sulfates or sulfate esters, reducing the activity of hydroxyl groups.

2. Amino Group Reactions:

   • Acidic gases like H₂S and NH₃ can react with amino groups in epoxy curing agents, producing thiols or amines. These compounds can lower the cross-linking density of the curing agent, resulting in reduced coating performance.

3. Carboxyl Group Reactions:

   • Acidic gases such as SO₂ and H₂S can react with carboxyl groups in epoxy curing agents, forming sulfonates or sulfites. These compounds can decrease the activity of the curing agent, affecting the final performance of the coating.

Mitigation Strategies

To address the impact of acidic gases on epoxy curing agents, the following strategies can be employed:

1. Select Appropriate Curing Agents: Use curing agents with stronger acid resistance or choose types better suited to resist corrosion from acidic gases.

2. Optimize Environmental Conditions: Control the application environment of epoxy coatings to avoid direct exposure to acidic gases. For example, in environments with high concentrations of acidic gases, consider adding a protective layer on the coating surface to isolate it from direct contact.

3. Use Additives: Incorporate additives that enhance resistance to acidic gases, such as organosilicon compounds, fluorinated chemicals, or other specialized compounds, to improve the coating’s corrosion resistance.

4. Monitoring and Maintenance: Regularly monitor the environmental conditions of epoxy coatings, promptly addressing the effects of acidic gases. Additionally, conduct routine maintenance and inspections to ensure coating performance remains unaffected.

The interaction between epoxy curing agents and acidic gases is a complex process involving multiple chemical reactions and physical changes. To ensure the quality of epoxy coatings, it is essential to deeply understand the principles of these interactions and adopt measures to mitigate or eliminate their adverse effects. By selecting appropriate curing agents, optimizing environmental conditions, using additives, and implementing monitoring and maintenance, the impact of acidic gases on epoxy curing agents can be effectively managed, thereby extending the service life and reliability of coatings.