Resin, modifier, and cross-linking agent can be changed to create a custom epoxy that works under very specific conditions. These properties make epoxy resins the material of choice for a wide variety of applications and conditions. Epoxy (EP) resins are thermosetting polymers, which means that they cure in an altered form from their liquid state and cannot be remelted like thermoplastics. Thermoplastics are generally recyclable for this reason, while thermosets are generally not.
Other thermosets include polyester, urethane, melamine and phenolic. Information on these thermosets and other thermoplastics can be found in our Resin Types guide. It has excellent gap-filling properties. Epoxy is resistant to cold, radiation and steam.
Superior epoxy performance remains when exposed to harsh environmental conditions. Due to the presence of significant polarity, epoxies wet and adhere exceptionally well to many surfaces. The mechanical properties of cast epoxy outperform most other moldable plastics. Epoxies are excellent electrical and thermal insulators.
Can be formulated to withstand temperatures up to 290°C (550°F). Are selectively resistant to a wide range of environments and chemicals. They are highly resistant to caustics, oils and many solvents with fair resistance to acids. Chlorinated hydrocarbons and some organic acids will attack epoxy systems.
Epoxies discolor when exposed to ultraviolet energy. Tend to brittleness, but can harden at lower use temperatures (120°C, 250°F, 95% RH), significant loss of properties has been reported. However, polymer degradation (reversion), as with some silicones and polyurethanes, is extremely rare. Epoxy resins are a class of thermosetting polymers made of monomers containing at least two epoxy groups.
Provides strong adhesion, chemical resistance and other specialized properties. Because of these qualities, epoxy resins are used in a variety of industrial and consumer products. Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers that contain epoxy groups.
The epoxy functional group is also collectively referred to as epoxy. The IUPAC name for an epoxide group is oxirane. Epoxies are not normally used in the outer shell of a ship because they deteriorate from exposure to ultraviolet light. Epoxies are used in a variety of industrial and consumer applications, due to their durability, strong adhesion, chemical resistance, and other specialized properties.
When cured, epoxy resin results in a thermosetting plastic with high chemical resistance and low water absorption. Important epoxy resins are produced from the combination of epichlorohydrin and bisphenol A to give diglycidyl ethers of bisphenol A. However, these resins contain hydroxyl groups throughout the main chain, which can also undergo other cross-linking reactions, e.g. Epoxy resin is an incredibly effective adhesive and sealant and has significant resistance to water, chemicals, abrasion and other physical stress factors.
Catalysts are added in much smaller proportions than epoxy hardeners, usually a few drops per ounce of resin. Epoxy resins can be thought of as including pure epoxy resins, thermosetting polyester resins, and vinyl ester resins, although polyester thermosets are actually a separate species. For this application, epoxy resin is preferred because of its higher reactivity, compared to polyesters and vinyl esters. In principle, any molecule containing a reactive hydrogen can react with the epoxy groups of the epoxy resin.
Because aliphatic epoxies have a lower electron density than aromatics, cycloaliphatic epoxies react less easily with nucleophiles than epoxy resins based on bisphenol A (which have aromatic ether groups). Epoxy Europe has developed a safety brochure with guidance on the safe handling of epoxy resins in industrial environments. Polyester resins are typically of low strength unless used with a reinforcing material such as fiberglass, are relatively brittle unless reinforced, and have low adhesion. When using latent hardeners, the epoxy resin and hardener can be mixed and stored for some time before use, which is advantageous for many industrial processes.
Epoxy resins are used in the aerospace industry for aircraft and satellite systems as a binder for reinforcements such as glass and carbon, helping to make them strong and light. Additional information on thermoset resins can also be found on the Thermosetting Resin Formulators Association website. . .
