1、Control of Pore Sizes in Epoxy Monoliths and Applications as

We discussed the effects of the porous structures of monoliths on their physical properties, such as tensile strength, elongation, elastic modulus, and glass transition temperatures.

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-friendli-ness and mechanical functionality have emerged as vulcanization properties.

3、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.

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. Epoxy resins are...

Influence of different composite curing agents on the rapid curing

According to the comparison of pore structure characteristics, it can be concluded that as the content of type-B fast curing agent in the composite curing agent increases, both the pore size and porosity of the cured EP system increase, leading to a higher concentration of internal pore defects.

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.

The epoxy resin system: function and role of curing agents

The allyl group epoxidation was more effective in producing an epoxy 557 monomer without side reactions. This was because magnolol and MGOL-EP have the potential

Effects of Curing Agents on the Adhesion of Epoxy Resin to Copper: A

Although the adhesion of epoxy resins has been extensively studied using density functional theory (DFT) calculations, few studies have evaluated the effect of hardener molecules.

昆明理工大学材料学科2016

[1339] K. Zhang, Y. Gu, M. Li, S. Wang, Z. Zhang, Effects of curing time and de-molding temperature on the deformation of glass fiber/epoxy resin prepreg laminates fabricated by rapid hot press, Polym Polym Compos, 27 (2019) 301-313.

Surface Chemistry and Molecular Dynamics of Epoxy Resin

The results demonstrated that post-curing enhances the properties of epoxy resin by promoting further cross-linking, reducing residual unreacted groups, and forming a more extensive covalent network. This results in improved mechanical and thermal stability.

In modern industrial manufacturing, epoxy resin is widely used due to its excellent mechanical strength, chemical stability, and electrical insulation properties. It plays a crucial role in the fabrication of various composite materials. the curing process of epoxy resin involves complex chemical reactions that require the participation of multiple substances. In this process, a critical auxiliary material—the pore-forming agent—plays an indispensable role.

The primary function of pore-forming agents is to promote the formation of bubbles within the epoxy resin. These bubbles provide essential space during the curing process, resulting in final products with enhanced mechanical properties and reduced defect rates. Additionally, pore-forming agents help adjust the material’s density and coefficient of thermal expansion, meeting specific application requirements.

I. Types and Selection of Pore-Forming Agents

1. Types of Pore-Forming Agents

• Organic Solvent-Based: These include volatile organic compounds such as acetone and toluene. They evaporate rapidly during curing, leaving behind numerous pores.
• Inorganic Salt-Based: Examples include potassium hydroxide and sodium hydroxide. These do not evaporate but instead generate gases through chemical reactions, forming pores.
• Polymer-Based: Substances like sodium polystyrene sulfonate release gases slowly during curing, creating stable porous structures.

2. Criteria for Selecting Pore-Forming Agents

• Application Requirements: Choose agents based on the product’s operating environment and performance needs. For example, organic solvent-based agents may be suitable for high-strength applications, while inorganic salts or polymers are preferred for low-density or low-thermal-expansion materials.
• Cost Considerations: Different agents vary significantly in cost. Organic solvents are cheaper but may harm the environment, whereas inorganic salts are more eco-friendly but expensive.
• Process Compatibility: Ensure compatibility between the pore-forming agent, epoxy resin, and other additives to maintain product quality and performance.

II. Mechanisms of Pore-Forming Agents

1. Chemical Reaction Mechanism

Pore-forming agents often contain substances that react with the epoxy resin to produce gases. During curing, these substances interact with functional groups in the resin, generating gases that form pores without altering the resin’s composition.

2. Physical Foaming Principle

Some agents rely on physical foaming. For instance, certain polymers gradually dissolve and diffuse into the resin. As curing progresses, these polymers solidify into network structures, creating pores without releasing harmful gases.

III. Effects of Pore-Forming Agents

1. Enhancing Mechanical Performance

By introducing pores, pore-forming agents significantly improve mechanical properties. Pores act as stress-relief points, reducing internal stress concentrations and crack initiation risks. This strengthens the material’s load-bearing capacity, compressive strength, and overall toughness.

2. Reducing Defect Rates

Pores help minimize internal defects. During curing, they absorb and disperse stress, lowering the risk of crack propagation. Additionally, pores fill microscopic gaps in the resin, further reducing defect rates.

3. Improving Thermal Expansion Properties

By adjusting the type and ratio of pore-forming agents, thermal expansion properties can be precisely controlled. Different agents have varying coefficients of thermal expansion, allowing optimized material performance—critical for high-temperature applications.

Pore-forming agents are vital to the curing process of epoxy resin. By selecting the appropriate type and proportion, they enhance mechanical properties, reduce defects, and improve thermal expansion behavior. factors such as cost, environmental impact, and process compatibility must also be considered. In the future, advancements in materials and technology may lead to more efficient and eco-friendly pore-forming agents, expanding the potential applications of epoxy resin.