Hardeners, also known as curing agents or catalysts, play a crucial role in the formulation of epoxy resins, transforming them from a liquid state to a solid state through a polymerization process. The selection of the appropriate hardener is essential to achieve desired properties and performance in the final epoxy product. Next, I will describe some of the most commonly used hardeners.
Aromatic hardeners
Aromatic amines are commonly used as hardeners in epoxy formulations. They offer good chemical resistance and are often used in high-performance applications. However, they may have lower moisture resistance compared to aliphatic amines.
Aliphatic hardeners
Aliphatic amines are fast-curing hardeners that provide excellent chemical and mechanical resistance. They are ideal for applications requiring rapid service and good overall performance.
Cycloaliphatic hardeners
Cycloaliphatic amines provide a good combination of properties, including excellent heat and corrosion resistance, as well as good flexibility.
Polyamine
Polyamines are versatile hardeners that offer a balanced combination of properties, including good chemical resistance, flexibility, and moisture resistance. They are commonly used in various coating and adhesive applications.
Polyamide
Polyamides are moderate-curing hardeners that offer good chemical and moisture resistance. They are commonly used in coatings and adhesives, providing a good balance between flexibility and mechanical properties.
Phenalkamines
Phenalkamines are specialized hardeners derived from phenol and amines. They offer excellent chemical and moisture resistance, as well as good adhesion to various substrates. They are commonly used in applications requiring high performance under harsh conditions, such as marine and industrial coatings.
Anhydrides
Anhydrides are slow-curing hardeners that offer excellent thermal and electrical resistance. They are ideal for applications requiring low-temperature curing and high dimensional stability.
Phenols
Phenols, such as bisphenol A, can act as hardeners in the presence of amines or anhydrides. They offer good chemical and the
Isocyanates
Isocyanates are fast-curing hardeners that offer excellent abrasion, chemical, and weather resistance. They are ideal for applications requiring high mechanical strength and durability.
Mercaptans
Mercaptans are slow-curing hardeners that offer good flexibility and impact resistance. They are commonly used in applications requiring high elongation and crack resistance.
