The world of adhesives is vast. There are many different types and many different ways to describe them. In this series of short videos, we will focus on their base chemistry. Today, let's talk about epoxy adhesives. Epoxy adhesives, also known as epoxies, are structural adhesives. This means they become part of the structure they are bonded to. Epoxy adhesives consist of two components. The epoxy resin and a hardener element, usually an amy. The type of epoxy resin can be different depending on what's expected from the glue. For example, if more viscosity and greater chemical resistance are needed, a different type of resin will be used. The three main types of epoxy resins are bisphenol A, bisphenol F and novelac. Epoxy adhesives can be used for bonding dissimilar materials with a strong and durable bond. What are the main advantages of epoxies? Epoxies are the strongest glue you can get. They can deliver strengths in excess of 30 megapascals, which means they can replace welding. All types of epoxies have good chemical resistance. They will not break down when exposed to chemicals. They will also withstand high temperatures as they have very good heat resistance. Epoxies have good fatigue resistance. They can be put under a lot of stress and a number of times and maintain their strength very well. As we said, epoxies can bond to dissimilar materials. They do not need to bond the same substrates to achieve a very strong bond. Epoxy adhesives present drawbacks as well. Cure time is usually gradual and can be affected by temperature. The lower the temperature, the slower the cure will be, meaning it can take a few days before reaching full cure. Most epoxies will be brittle. This lack of flexibility is a problem when bonding something that is likely to vibrate or move. Surface preparation is needed with epoxy adhesives. The surface will need to be cleaned and abraded to achieve a strong bond, which can be a time consuming and labour intensive process. Epoxies undergo an exothermic reaction as they cure. This means epoxia adhesives will generate heat, especially if used in large quantities. This exothermic heat can potentially damage the substrates and affect the bond. Epoxies compose health and safety risks. If in contact with the skin or eyes, they can cause skin sensitization, irritation or allergic reactions. The use of proper protective equipment will mitigate these risks. Overall, epoxia adhesives are strong, durable and chemically resistant, making them an excellent adhesive option. If you want to know more about other types of adhesives, make sure to subscribe to our channel.