1、Curing reactions of epoxy powder coatings in perspectives of chemical

This review discusses the types, reaction principles, characteristics of curing agents and accelerators that participate in the curing reaction with different epoxy resins.

2、Novel Thermal Latent Curing Agents for Epoxy Resins Based on Dual

Herein, we present a dual-locked thermal latent curing agent based on aminopyridines, protected by amidation and N-oxidation, designed to enhance both pot life and final curing efficiency.

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

Curing agents are critical components of aqueous epoxy resin systems. Unfortunately, its uses and applications are restricted because of its low emulsifying yields.

4、Surface Chemistry and Molecular Dynamics of Epoxy Resin

In this study, we investigate the main reactions occurring on the surface of DEGBA/DEGBF epoxy resin following curing, post-curing, and thermal post-curing processes using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS).

5、Heterogeneous dynamics in the curing process of epoxy resins

In this study, the microscopic dynamics in the curing process of a catalytic epoxy resin were investigated under different temperature conditions utilizing X-ray photon correlation...

Surface Chemistry and Molecular Dynamics of Epoxy Resin: Insights from

In this study, we investigate the main reactions occurring on the surface of DEGBA/DEGBF epoxy resin following curing, post-curing, and thermal post-curing processes using Time-of-Flight...

Thermal oxidative degradation of cyanate

Thermal oxidative degradation behaviors of epoxy resin cured with cyanate ester and conventional amine are experimentally evaluated in terms of heat resistance and flame retardancy, and the degradation mechanisms are further investigated using ReaxFF molecular dynamics simulations.

Thermal curing of epoxy resins at lower temperature using 4

In this study, we present N -methyl- N -pyridyl amide derivatives as thermal latent curing agents for use at lower temperatures, along with their mechanism of epoxy curing through the generation of the highly reactive 4- (methylamino)pyridine (4MAPy) (Figure 1).

The curing and thermal transition behavior of epoxy resin: a molecular

These phenomena can be illustrated by the change of the reaction energy barrier, flexibility of chains and the cohesive energy density in the molecular simulation of the curing process.

Theoretical studies of mechanisms of epoxy curing systems

epoxy resin, a particular curing agent and/or a particular catalyst. The examination of all possible reaction pathways for each curing system can allow us to predict the most preferable pathway in the system and can enable the development of a more accurate kinetic model for the system.

In modern industrial and construction fields, epoxy resin applications are ubiquitous. Renowned for its exceptional adhesive properties, mechanical strength, and corrosion resistance, epoxy resin has become the top choice for material bonding and repair. the curing process of epoxy resin is not without challenges. A critical chemical change—the oxidation of curing agents—plays a pivotal role in determining the success of the curing process. This article delves into the mechanisms, impacts, and solutions related to the oxidation of epoxy resin curing agents.

I. Composition and Function of Epoxy Resin Curing Agents

Epoxy resin is a high-molecular-weight compound containing epoxy groups (-C=C-), with numerous carbon-carbon double bonds along its molecular chain. These double bonds serve as reactive sites for the curing reaction, enabling cross-linking with various curing agents to form a three-dimensional network structure. This structure imparts superior mechanical and chemical resistance properties to the material.

The primary role of curing agents is to introduce additional reactive groups, such as hydroxyl (-OH) or amino (-NH₂) groups, into the epoxy resin. These groups react with the epoxy double bonds, driving the curing process. Different curing agents exhibit distinct chemical properties and reaction characteristics, making them suitable for specific epoxy resin formulations.

II. The Oxidation Process of Curing Agents

During the curing of epoxy resin, the oxidation of curing agents is an unavoidable step. Upon mixing with epoxy resin, curing agents gradually lose some of their reactive groups, reducing their capacity to initiate cross-linking reactions. This oxidation is typically triggered by environmental factors such as oxygen, moisture, or light radiation.

Oxidized curing agents exhibit diminished activity, leading to incomplete curing. This results in microcracks or porosity within the material, compromising its durability and reliability.

III. Impact Analysis

1. Material Performance: Oxidation directly affects the final properties of cured epoxy resin. High levels of oxidation may cause inadequate strength, reduced toughness, and impaired thermal and chemical resistance.

2. Process Control: The oxidation of curing agents is influenced by temperature, humidity, and light exposure. Strict environmental controls, such as sealed containers or light-proof measures, are necessary to mitigate oxidation during processing.

3. Cost-Effectiveness: While moderate oxidation can sometimes enhance performance (e.g., through adjusted curing agent ratios), excessive oxidation leads to resource wastage and degraded material properties.

IV. Solutions and Recommendations

To address curing agent oxidation, consider the following strategies:

1. Optimize Curing Agent Selection: Choose curing agents with low oxidation susceptibility, such as those with a low oxygen index.

2. Environmental Control: Minimize exposure to oxygen and moisture using inert gas protection, vacuum drying, or humidity-controlled environments.

3. Additive Integration: Incorporate antioxidants or UV absorbers into the resin system to slow oxidation rates and improve longevity.

4. Rigorous Monitoring: Implement real-time process monitoring and periodic evaluations to detect and resolve oxidation issues, ensuring consistent material quality.

The oxidation of epoxy resin curing agents is a complex yet critical chemical process that profoundly impacts material performance, production efficiency, and cost management. By understanding this phenomenon, researchers and engineers can refine curing techniques, offering more reliable and efficient solutions for diverse applications.