An epoxy curing agent is a chemical substance used to cure epoxy resins by reacting chemically with the epoxy groups in the epoxy resin to form a cross-linked structure, thus making the epoxy resin a hard, durable solid material.
The primary role of epoxy curing agents is to enhance the hardness, abrasion resistance, and chemical resistance of epoxy resins, making them a long-lasting and durable material, which is an integral part of epoxy pultruded composites. This article shares how to choose the right epoxy-curing agent based on different factors:
According to curing conditions
- Curing at room temperature: If fast curing at room temperature is required, aliphatic amine curing agents such as ethylenediamine and diethylenetriamine can be selected; if the curing speed is not required to be high, and focus on operation time, polyamide curing agents can be selected.
- Heat curing: For high heat resistance and mechanical properties, aromatic amine curing agents, such as diaminodiphenylsulfone (DDS), etc., can be used; for low-temperature fast curing, modified amine curing agents with accelerators can be considered.
- Curing under special conditions: for curing in a humid environment, a wet curing curing curing agent can be selected; for a light curing system, curing agent with photoinitiator and epoxy acrylate can be selected.
According to the performance requirements
- Mechanical properties: if high hardness and high strength are required, anhydride curing agents can be selected; if good flexibility and impact resistance are required, toughening curing agents such as polysulfide rubber are more suitable.
- Chemical resistance: high requirements in acid, alkali, and solvent resistance, phenolic resin curing agent or some modified amine curing agent is more suitable.
- Heat resistance: For high-temperature environments, such as above 200℃, a silicone curing agent or curing agent with a polyaromatic structure can be considered.
According to the usage environment
- Indoor environment: high environmental protection requirements, a water-based epoxy curing agent or low volatile aliphatic amine curing agent is more suitable.
- Outdoor environment: good weather resistance is required, alicyclic amine curing agents with good UV resistance are more suitable.
- Special environments: In environments with high hygiene requirements such as food and medicine, non-toxic or low-toxic epoxy curing agents such as food-safety certified polyamide curing agents need to be selected.
Consider process requirements
- Operation time: For a long operation time, choose a latent curing agent, such as dicyandiamide, etc. For short operation and curing time, choose fast curing aliphatic amine curing agent.
- Curing Appearance: For a colorless and transparent curing appearance, choose alicyclic amine curing agents, etc. For low color requirements, choose lower-priced general amine curing agents.
Combined with the cost factor
- Under the premise of meeting the performance requirements, compare the price and dosage of different curing agents. The price of common amine curing agents is relatively low, while some special performance curing agents such as fluorine-containing and silicone-containing curing agents are more expensive.
Post time: Mar-18-2025
