Resulting Properties
Dicyandiamide is considered to be the workhorse catalyst of one-component epoxy adhesives due to its ease of use, excellent performance properties, long shelf stability, and low toxicity. In mixtures with DGEBA, it has demonstrated a room temperature storage life in excess of 4 years. Dicyandiamide, a solid powder, is usually added to the solid epoxy resin in concentrations of about 3-10 phr. Cures can be conducted in the range of 120-175°C but are very slow at the lower temperatures. As a result, it is common practice to add accelerators such as BDMA and mono- or dichlorophenyl substituted ureas to these systems.