What is Epoxy Resin: Types, Uses, Chemical Properties, and How it Works

Epoxy resin is a highly versatile product used in various industries. It adheres to different materials including metal, glass, wood, and fabric.

The incredible heat-resistant property makes it a great adhesive product for anyone to craft useful items like coasters, tumblers, bookmarks, shakers, etc.

With all the benefits, it’s easy to understand why its popularity is increasing day by day. Unfortunately, many people using epoxy resin don’t even know exactly what it is!

But with today’s discussion, that’s about to change!

What is Epoxy Resin?

Epoxy resin (polyepoxides) is a certain type of organic compound containing epoxide groups. It’s made up of carbon chains that are linked to other elements like nitrogen, oxygen, and hydrogen. The link happens through a covalent bond.

This allows elements sharing 2 electrons to bond together. As a result, the polymers become elastic and tough. This makes them ideal for various applications.

In simpler terms, polyepoxide is a thermoset resulting from a reaction of 2 or more compounds. This reaction radiates heat and converts the material from a liquid to a cured/ solid form. Note, the chemical reaction can last for many hours.

What Is Epoxy Resin Made Of?

As you can see, the epoxy resin contains 2 terms. So, to understand what makes up this class of chemicals, we need to understand these terms first.

1. Epoxy

Polyepoxide is an informal name for the epoxide group. Moreover, it’s used to describe the cured end products or basic components of epoxies. Simply put, epoxy refers to a polyepoxide when it’s in its uncured/ liquid state. A polyepoxide comprises 2 primary parts; the hardener (curing agent) and the resin. When you mix the curing agent and resin, a chemical reaction ensues!

2. Resin

Resin is made up of epichlorohydrin and bisphenol. One need you need to note though is that there are many types of bisphenol. A combination of phenol and acetone is the most common bisphenol type.

Wait, where can you get these compounds from?

Initially, phenol was extracted from coal. Things have changed though! Today, like many other popular compounds, it’s extracted from petroleum. On the contrary, epichlorohydrin is extracted from a substance known as ally chloride. This propylene tub chemical contains chlorine.

Various Types of Epoxy Resin

First of all, epoxy is a small part of the resin family. There’re various other types of resins available. So let’s start by looking at some of the most common types out there;

UV Resin

Unlike most types of resins, UV resin isn’t made of 2 components; resin and hardener. Instead, it only comes in one ready-to-use component. For that, there will be no mixing involved. To trigger the chemical reaction, you just need to expose it to UV light. This enables it to set very quickly.

Polyurethane Resin

This is another resin type that is commonly used for casting molds. It’s a very durable set when exposed to high temperatures. Note, polyurethane resin can come in various forms. This makes it ideal for use in different industries. You can find it in most appliances as well as in the car industry.

Polyester Resin

This type features a fiber structure, and it’s both strong and water-resistant. It’s often used to build boats or make pools and ponds.

Epoxy Resin

Among all types of resin we’ve looked at above, epoxy resin is the most versatile form. For that, you can use it for a wide range of applications. This includes creating bookmarks, coating countertop, or making attractive resin tumblers, etc.

However, epoxy resin can be classified into 2 principal categories- Non-glycidyl & Glycidyl. Non-glycidyl resins can either be cyclo-aliphatic and aliphatic. On the other hand, the glycidyl variety can fall under 3 different subcategories.

This includes; Glycidyl-amine, ether, and ester. Among these, glycidyl-ether is the most common subcategory, especially in bisphenol and novolac resins.

1. Bisphenol

Most commercial polyepoxides in the market today fall under this category. They’re produced when epichlorohydrin contacts bisphenol-A in presence of a catalyst. Bisphenol-A comes in a wide range of molecular weights. This makes them very versatile in terms of application.

Another benefit is that this compound has great physical properties and chemical resistance. Moreover, you can cure it using different agents at the ideal ambient temperature.

2. Novolac

The novolac variety is produced when methanol (formaldehyde) and phenol react. When novolacs are mixed with epichlorohydrin, they react to form novolacs containing resides. Some of these residues include ECN (epoxycresol novolac) and EPN (epoxyphenol novolac).

This type of polyepoxide doesn’t contain volatile organic compounds (VOCs) or solvents. For that reason, they’re very safe to use. You don’t even need respirators when working with them. Moving on, novolac epoxies have a high level of bonding strength. Also, they’re quite durable and have good coverage levels.

3. Other types

Epoxy resins are also available in other types. This includes; halogenated diluents and glycidyl amine epoxy resins.

How Epoxy Resin Works

How Epoxy Resin Works

Epoxy is a thermoset or thermosetting resin. This means that it’s a polymer that sets or cures depending on the surrounding heat/ temperature. When it hardens, the process is irreversible! That’s because the curing process introduces a polymer chain linked by covalent bonds.

Being an epoxide, epoxy is more reactive to other chemical compounds. One thing you need to note though is that the compound contains unreacted epoxide. In other words, pure epoxy is extremely stable at room temperature.

At the same time, it’s very vulnerable to reactions with other chemical compounds. In this case, the other chemical compound is the curing or hardening agent!

To trigger a chemical reaction, you need to mix the resin with the hardener. Depending on the reaction type, cured epoxy will either be honey-like or more viscous. The actual molecular weight of cured compound will determine its application.

What is Epoxy Resin Art?

Epoxy resin art is the use of polyepoxides to create art items and pieces. This trend originated in the USA, Australia, Europe, and Canada. It allows crafters to create artworks that match their brilliance, luminosity, and clarity.

Resin art involves designing paintings, creating resin coasters, and other types of castings. The art of casting different resin pieces is popularly known as resin casting. Apart from creating classical casting, it enables you to embed items in your pieces. This can include objects like stones, glitter, natural materials, and so on. As a result, you’ll end up with unique beautiful art objects.

To undertake resin art, you need to mix the 2 components (resin & hardener) first. This triggers a chemical reaction that forms a high, clear surface after hardening. Afterward, you can sand, polish, or even paint the cured surface.

Crafters consider resin a good art modality due to the finish quality it gives the artwork. It adds accentuating colors, glows, and enhances the durability of the art pieces. Moreover, it’s thicker than other finish products like varnish.

This enables it to protect your art objects from elements like weather and chemicals.

Epoxy coating also preserves countertops and protects them from scratches. Better still, it’s a versatile material and allows numerous design possibilities. For that, you can use it on various surfaces to make your pieces stand out.

Advantages of Epoxy Resin

Epoxy is currently being used in various industries. Thanks to the numerous benefits it offers. Some of those benefits are;

1. Withstands Various Elements

On curing, this compound can resist moisture and oil. Better still, it can withstand attacks from many chemicals including acids and solvents. On top of that, it has good tolerance to high temperatures, shock, and high vibrations. All these factors make it a great compound to use in various environments and settings.

2. Highly Versatile

This chemical compound can adhere to a wide range of materials. You can apply it to different materials including wood, stone, concrete, plastic, and glass. This makes it ideal for industries such as HVAC, construction, marine, and so on.

3. Low Shrinkage

Polyepoxides tend to have a low shrinkage time during the curing stage. This helps to minimize internal stress while enhancing its adhesion to the surface.

4. Strong Mechanical Properties

Some mechanical properties exhibited by polyepoxides include; compression, resilience, flexion, and tensile strength. Epoxy has superior mechanical properties as compared to large diffusion resins like polyester. This enables it to resist degradation over time, making it ideal for industrial uses.

5. Attractive appearance

From an aesthetic perspective, polyepoxides gives surfaces a shiny gloss-clear coating. However, you can add colors and other compounds to the resin once it cures. This gives homeowners and contractors a cost-effective option to avoid high-priced materials. More importantly, it ensures the surfaces have a superior, abrasion-resistant finish.

Disadvantages of Epoxy Resin

The main drawback associated with this compound is that it contains harmful chemicals. Being exposed to epoxies, either through contact or inhalation can affect one’s health. It can cause acute issues like; allergic skin reactions, skin irritation, and headaches. Moreover, prolonged exposure to this compound can cause breathing problems and asthma-like symptoms.

FAQs

1. Can you color epoxy resin?

Pure epoxy is usually transparent, clear, and colorless. However, you can color it with various types of pigments. Some of these colors are; airbrush colors, alcohol inks, and powdered color pigments. Note, avoid water-based paints since they can prevent the polyepoxides from hardening fully.

2. How do I remove epoxy resin?

Polyepoxide has high adhesives properties when it cures. For that reason, it’s quite difficult to remove it from surfaces by mechanical means. So, instead of scrapping it off the surfaces, adopt other removal techniques.

The most effective method of removing hardened epoxy is to use acetone. However, you need to ensure the space has adequate ventilation.

3. What surface does epoxy resin not adhere to?

Although epoxy is very versatile, there are some surfaces it doesn’t stick to. This includes silicone, masking tape, polyethylene plastic, wax, and greasy surfaces.

4. What’s the difference between epoxy and resin?

Technically, epoxy and resin are the same things. However, there are different types of resins out there. They include; casting, polyester, and epoxy resin. Each of these compounds has unique properties and compositions.

It’s also worth noting that epoxy adhesive and epoxy resin are 2 different products!

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