Have you ever stopped to think about how often we make regular use of things we know very little about? For example, most of us can use computers proficiently, but how many of us actually comprehend the science behind their inner workings? Plenty of us have probably used epoxy too, but how many of us know what epoxy is made of?
Epoxy and Epoxy Resin
Perhaps the first thing to understand about this class of chemicals is this: there’s a difference between epoxy and epoxy resin. The difference is simple. Epoxy is merely cured epoxy resin. Or in other words, epoxy resin is epoxy adhesive in its liquid form. For any epoxy, there are two primary parts to the equation: the resin and the curing agent. When the resin and the curing agent react together the hardening process ensues.
The resin itself is made of bisphenol (and there is more than one type) and epichlorohydrin. The most common type of bisphenol is a combination of acetone and phenol. Maybe you’re asking yourself now: where on earth does phenol come from? Well, when first it was discovered it came from coal tar, but nowadays, chemist extract if from petroleum (like so many other useful compounds). Now as far as epichlorohydrin is concerned, well, it’s derived from something called allyl chloride.
As it turns out, the curing agent plays a big role in how the epoxy turns out when it’s cured. There are numerous curing agent recipes, but one of the more common is a combination of amides and polyamides (which amounts to a variation of ammonia—the difference being the replacement of a hydrogen atom with a carbon + oxygen pair).
Maybe you feel like you better understand epoxy now, or maybe you don’t. But either way, you can still make use of the product for a variety of purposes. Whatever you use it for, there is one thing to remember: epoxy is temperature sensitive. In fact, most epoxies cure best at temperatures far above the normal range for ambient air. Keeping epoxy curing at the ideal temperature becomes increasingly difficult when the needle drops. But, then again, that’s why epoxy curing solutions exist.