Epoxy resin, also known as polyepoxide, is a type of adhesive with a high level of flexural strength that is suitable for both domestic and commercial purposes. Formed of two parts, it is usually mixed in ratios of 2:1 to 4:1 resin to hardener.
It also has a long pot life or working time, with the fast variety giving about 15 minutes before gelling and the regular/slow variety expected to give roughly 100 minutes. Epoxy resin is a popular material used in construction and manufacturing due to its tough and adhesive qualities, as well as its resistance to chemicals.
It has a wide range of uses, including the building of electronic components such as fiber optics and electrical circuit boards. Epoxy resins are classified under two main types – glycidyl and non-glycidyl.
Glycidyl
Glycidyl resins are further divided into three subcategories: glycidyl-ether, glycidyl-ester, and glycidyl-amine. Among all glycidyl resins, glycidyl-ether epoxies are the most popular, especially those of the bisphenol and novolac variety.
Bisphenol-A diglycidyl ether (DGEBA) is a variety of commercial epoxy resin that is used in many products. It is created when bisphenol-A reacts with epichlorohydrin in the presence of a basic catalyst. This type of epoxy resin has the lowest molecular weight and is used in many products.
Novolac epoxy resins are made from the reaction of phenol and methanol (formaldehyde). This creates a carcinogenic substance called epichlorohydrin, which is then reacted with novolacs to form epoxyphenol novolac (EPN) or epoxycresol novolac (ECN).
These epoxies do not contain any solvents or volatile organic compounds (VOCs), making them extremely safe to use without the need for respirators. They also have a high level of adhesive strength and coverage. Applying these resins provides protection and durability.
Non-Glycidyl
Non-glycidyl resin types include aliphatic and cyclic-aliphatic.
Aliphatic epoxy resins are either produced as a result of double bond epoxidation or reaction with epichlorohydrin. Double bond epoxidation involves cycloaliphatic epoxides and epoxidized vegetable oils. Reaction with epichlorohydrin produces glycidyl ethers and esters.
Cycloaliphatic epoxides feature one or more aliphatic ring in the molecule containing the oxirane ring. They have a defined aliphatic structure, high oxirane content, and absence of chlorine. This makes for low levels of viscosity, good weather resistance, low dielectric constants, and high Tg.
Halogenated epoxy resins are often used for special properties or applications that require flame resistance or electrical properties. Brominated bisphenol A resins are often preferred for these purposes, but they can be expensive to produce and have a low Tg.
Epoxy diluents are created by glycidylating aliphatic alcohols or polyols. The materials produced as a result of such processes may be either monofunctional (dodecanol glycidyl ether), difunctional (butanediol diglycidyl ether), or higher functionality (trimethylolpropane triglycidyl ether).
Glycidylamine epoxy resins are a type of glue that is formed when two chemicals, aromatic amines and epichlorohydrin, are mixed together. These resins have a high level of functionality, which means they can be used for a variety of purposes.
Epoxy Resin for Buildings
Epoxy resins can help improve the durability of structural parts, engineering adhesives and paints, making them ideal for use in building and construction applications. This can help to increase the lifespan of buildings, as well as reduce the need for refurbishing and repainting.
Epoxy-enhanced paints not only dry quickly, but they also provide a tough and long-lasting coating that can protect factory cast iron, cast steel, and cast aluminum applications from sustaining damage from things like impacts or bumps.
Epoxy coatings can also include anti-corrosive primers and abrasion- and fire-resistant coatings to help further support metal casings and improve their overall durability. Epoxies are an important type of flooring material, especially in environments that need to be kept sterile, such as medical facilities and food-processing plants.
The durability of epoxy-coated floors means that they can withstand stronger cleaning products, making them easier to keep clean. It’s often used in high-performance and decorative applications such as terrazzo, chip, and colored aggregate flooring.
Epoxy flooring can also be improved with the addition of contrasting vinyl chips to the top epoxy layer, or other additives like grit to give floors an anti-skid texture. Epoxy resins are used to create composite pipes and tanks, as well as coatings for more traditional steel products.
The lining of epoxy pipes is usually durable and resistant to chlorine and microbes, making it a potential replacement for old piping. Epoxy adhesives offer more heat- and chemical-resistance than other types of glue, making them ideal for laminating wood used in construction, like decks, walls, and roofs. Epoxy adhesives can also be used to bond wood to metal, glass, stone, and some plastics.
Key Takeaway
Epoxy resin can help improve the durability of structural parts, engineering adhesives and paints. This can help to increase the lifespan of buildings, as well as reduce the need for refurbishing and repainting. It is therefore ideal for use in building and construction applications.
