1、Amine/epoxy stoichiometric ratio dependence of crosslinked structure

ABSTRACT Epoxy-amine thermosetting resins undergo different reactions depending on the amine/epoxy stoichiometric ratio (r). Although many desirable properties can be achieved by varying the stoichiometric ratio, the effects of the variation on the crosslinked structure and mechanical

2、Dual

Sequential dual-curable thermosets based on off-stoichiometric and stoichiometric amine–epoxy formulations have been developed, employing different reactivities of two curing agents in terms of temperature.

3、Calculation of Epoxy and Curing Agents

The calculation of epoxy-to-curing agent ratios is a complex process requiring comprehensive consideration of multiple factors. By employing scientific methods and technical tools, the final product can meet specific performance requirements and deliver optimal results in practical applications.

4、Off

The cross-linking structure and physical properties of epoxy resins cured with amine under off-stoichiometric ratio conditions were examined.

5、Curing kinetics and performances of synthesized multi

In this study, two novel multi-amine compounds with more active groups, modified dicyandiamide (MDY) and branched polyamine (BPA), were synthesized and applied as the high-efficiency curing agents for epoxy powder coatings.

Amine curing of epoxy resins: options and key formulation

This paper provides an overview of the wide variety of amine hardeners, with an emphasis on polyetheramines from Huntsman Performance Products that can expand the capabilities of epoxy formulators into new applications.

Calculation of Epoxy Resins and Curing Agents

In particular, effective formulations are designed for mixing fast and slow curing agents, studying their effects on the curing behavior, curing quality, and mechanical properties of epoxy resins and elucidating their influence mechanisms.

Amine Curing of Epoxy Resins: Options and Key Formulation

As a general rule, use of a 1:1 stoichiometric ratio of amine hydrogen to epoxide groups will, when fully reacted, ensure maximum stability of the product. Such a stoichiometry may not, however, always provide the most desirable processing characteristics or combination of particular properties.

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.

MANUFACTURING OF COMPOSITES

Tertiary amines (no hydrogen on the nitrogen) are Lewis bases that cure epoxy resins in an entirely different manner than the aromatic and the aliphatic amines.

In modern construction and manufacturing industries, epoxy resin (Epoxy Resin) is widely used in various composite materials due to its excellent mechanical properties, chemical resistance, and electrical insulation. Amine curing agents (Amine Curing Agent) are critical components for achieving the curing of these high-performance materials. To ensure the final product meets expected performance standards, correctly matching the ratio of curing agent to resin is essential. This article explores how to calculate the ratio between amine curing agents and epoxy resins.

1. Understanding Basic Concepts

First, it is necessary to understand what amine curing agents are and the fundamental properties of epoxy resins.

• Amine Curing Agents: Compounds that promote the cross-linking reaction of epoxy groups, typically existing in trifunctional or tetrafunctional forms, such as polyisocyanates (PIDC) or multiamines (MDA).
• Epoxy Resins: A class of thermosetting polymers containing epoxy groups, known for their superior adhesive properties, mechanical strength, and chemical resistance.

2. The Importance of Ratio

The ratio refers to the mass ratio of the curing agent to the resin, directly impacting the physical and chemical properties of the cured material.

• Performance Impact: Different ratios lead to variations in hardness, flexibility, temperature resistance, and other properties. For example, increasing the proportion of curing agent enhances hardness and strength but may reduce flexibility; conversely, decreasing the curing agent improves flexibility but may lower hardness and strength.
• Cost Considerations: An appropriate ratio helps control costs, as excessive curing agent increases material expenses, while insufficient amounts may compromise performance.

3. Ratio Calculation Methods

For calculating the ratio of amine curing agents to epoxy resins, follow these steps:

1. Determine Required Performance: Identify key performance indicators such as maximum hardness, tensile strength, and flexural modulus based on application needs.
2. Select Appropriate Curing Conditions: Account for environmental factors like temperature and humidity during the curing process.
3. Refer to Standard Formulations: Use industry-standard formulation tables compiled by experts based on experimental data to ensure optimal performance.
4. Conduct Small-Scale Tests: Verify the feasibility and effectiveness of the formulation through trials before full-scale production.

4. Practical Case Analysis

Suppose we are developing a new electronic encapsulation material requiring epoxy resin and an amine curing agent. Laboratory tests reveal the following requirements:

• Hardness: 80 Shore D, tensile strength: 150 MPa, flexural modulus: 10 GPa.
• Curing time: 2 hours at 25°C.

Consulting standard formulation tables, we find that a mass ratio of epoxy resin to amine curing agent of 1:1 meets the performance targets. to further optimize results, small-scale testing is conducted.

Scientific ratio calculations ensure optimal performance of epoxy resins and amine curing agents in practical applications. This not only reduces costs but also enhances market competitiveness. When designing ratios, it is recommended to reference industry standards, professional literature, and conduct small-scale tests to validate formulation feasibility and efficacy.