1、Controllability of epoxy equivalent weight and performance of

Here we report the synthesis of a series of hyperbranched epoxy resins with different EEW (EHBP-n) through thiol-ene click reaction between thiol-ended hyperbranched polyesters and allylglycidyl ether.

2、novolac epoxy和Phenolic Epoxy 酚醛环氧浅谈

Epoxy phenol novolac (EPN) resins contain more than two epoxy groups per molecule and are therefore described as multifunctional epoxy resins. In other words these are polyepoxides obtained by reacting a phenolic novolac resin with epichlorohydrin. When cured, these provide a high cross-link density due to the increased epoxy functionality.

3、Silicone modified epoxy resins with good toughness, damping properties

The chemical structure of the siloxane-bridged epoxy resin was characterized by Fourier transform infrared spectroscopy (FTIR), 1 H-NMR and an epoxy equivalent weight (EEW) test. The modified epoxy resins showed better elongation at break and izod notched impact strength than neat resin.

4、Epoxy Resins, Monomers, and Derivatives

This chapter provides an in-depth review of epoxy resins, monomers, and derivatives, with an emphasis on their functional structures and crosslinking chemistry.

Modified Epoxy Resin Synthesis from Phosphorus—Containing

In this study, a phosphor-containing polyol was reacted with epoxy resin to provide a modified epoxy resin, PPME. Various amounts of PPME were blended with the mixture of DGEBA and D-230 to afford epoxy compositions.

Preparation and Application of Polyurethane

Epoxy resins always suffer from high brittleness and poor resistance to crack initiation and propagation due to their high cross-linked density. In this work, a highly tough, self-healable, degradable, and recyclable polyurethane-modified epoxy material was successfully prepared via combining long and flexible chains with dual dynamic covalent bond/hydrogen bond cross-linking networks into the ...

Epoxy resins containing epoxy

In this study, we synthesized PCL-grafted PR modified with epoxy end groups to strengthen the bond between the PR and epoxy matrix. The binding of the epoxy group of the PRs with the epoxy resin matrix is demonstrated by the suppressed PCL chain dynamics observed from the pulsed NMR measurements.

Development of waterborne epoxy

This work aims to develop a waterborne epoxy coating incorporated with modified natural rubber (NR) latex for improved performance.

Silicone Modified Epoxy Resins with Enhanced Chemical Resistance

UV resistance was highest in ES-11 (Hydrogenated Epoxy); lower silicon content improved stability ES-11 showed the best corrosion resistance; lower silicon content was more effective.

Rapid and in

The need for rapid, fast and nondestructive determination of the epoxy equivalent weight (EEW) of the resins was the underlying motivation to develop and propose an accurate and efficient method by means of micro-Raman spectroscopy. Three bands of interest that were assigned to the epoxide vibrations (around 640, 918 and 1250 cm −1), were marked.

In the field of modern materials science, epoxy resins, as a class of important thermosetting polymers, are widely favored for their excellent mechanical properties, chemical stability, and electrical insulation. traditional epoxy resins often have limitations in practical applications, such as long curing times, insufficient heat resistance, and poor solvent resistance. To overcome these drawbacks, scientists have developed modified epoxy resins by introducing specific functional groups or altering their molecular structures to enhance performance. Among these modifications, the determination of the epoxy equivalent is a critical parameter for evaluating the properties of modified epoxy resins, as it directly impacts the material's adhesive strength, mechanical performance, and resistance to environmental erosion.

The epoxy equivalent (EO) refers to the number of moles of epoxide groups present in 100 grams of epoxy resin. This parameter is crucial for understanding the chemical reaction between epoxy resins and curing agents, as epoxide groups react with active hydrogen atoms in curing agents to form a three-dimensional crosslinked network, endowing the material with superior mechanical properties. the epoxy equivalent not only reflects the chemical nature of the epoxy resin but also serves as an essential basis for assessing its potential applications.

The magnitude of the epoxy equivalent significantly influences the performance of epoxy resins. Generally, a higher epoxy equivalent indicates a greater number of epoxide groups per unit mass of resin, leading to a higher crosslinking density and stronger mechanical properties after curing. For example, epoxy resins with a high epoxy equivalent can provide better tensile and compressive strength while maintaining good toughness and wear resistance. This makes them highly promising for applications in aerospace, automotive manufacturing, and construction.

the epoxy equivalent is not a fixed value; it varies depending on the type of epoxy resin, synthesis process, and usage conditions. For instance, different classes of epoxy resins (e.g., aliphatic, aromatic, and cycloaliphatic epoxy resins) have distinct epoxy equivalent ranges. Additionally, the synthesis process affects the epoxy equivalent. By adjusting parameters such as polymerization temperature, catalyst type, or monomer ratio, the epoxy equivalent can be controlled to some extent.

In practical applications, determining the epoxy equivalent is vital for selecting appropriate curing agents and optimizing production processes. Choosing the right curing agent ensures sufficient reaction between the resin and curing agent, resulting in a stable crosslinked network. Accurate calculation of the epoxy equivalent allows prediction of the curing behavior and final performance of the resin, guiding production practices.

Beyond industrial applications, the determination of the epoxy equivalent holds significant scientific importance. By comparing the epoxy equivalents of different epoxy resins, researchers can deepen their understanding of the relationship between chemical structure and performance, providing theoretical foundations for the development of new high-performance epoxy resins. methods for measuring epoxy equivalents continue to advance, with emerging analytical techniques such as nuclear magnetic resonance (NMR) and infrared spectroscopy (IR) improving measurement accuracy and reliability.

The epoxy equivalent of modified epoxy resins is a multidimensional concept that encompasses the resin's chemical structure, synthesis processes, application scenarios, and performance evaluation. By studying and applying the epoxy equivalent, we can better understand the characteristics of epoxy resins and provide scientific guidance for material design and preparation. In future materials science research, the epoxy equivalent will remain a key factor, paving new paths for the development and application of high-performance epoxy resins.