Everything You Need To Know About Thermoset Polymers

We use plastics for all kinds of things today, from writing instruments to automotive parts to clothing layers. In fact, plastics are increasingly replacing materials across the board, offering higher temperature resistance and lower corrosiveness, amongst other things. If you are new to the plastics industry, here is everything you need to know about thermoset polymers.

What are Plastics?

First off, you may wonder, “What are plastics?” These synthetic materials are the cornerstone of low-cost, high-efficiency manufacturing. The term “plastic” itself refers to the material’s own malleability and moldability. The plasticity of plastics is part of what makes them so versatile. Manufacturers can press them into tubes, plates, microfibers, bottles, and much more.

The Place of Polymers

At the center of plastic is its unique chemical nature. The term polymer refers to the molecular phenomenon where singular units—called monomers—repeat in a chain. These molecular bonds can continue for a few iterations or for thousands, depending on the desired thickness of the plastic. So, a hard plastic water bottle likely has a longer polymer chain than a bendy water bottle. These linear polymer chains are the foundation of all plastics.

What are Thermoset Polymers?

Thermoset polymers are a specific type of polymer commonly used to make plastic products. Though there are many kinds of plastics, none have the unique and advantageous characteristics of thermoset polymers.

The Chemistry Behind Thermoset Polymers

Let’s begin with chemistry. The critical molecular aspect of these particular polymers is their crosslinking. Polymer chains typically exist separate from one another. However, thermoset polymers crosslink with one another to form a stronger bond. These bonds are what create thermoset polymer’s signature heat tolerance. Because these bonds are so strong, high temperatures do not cause a breakdown in the molecular structure.

The way manufacturers ensure this bonding is through a process called curing. This heat treatment and the molecular structure of the raw materials create crosslinking bonds in the third dimension. After the heat forming, thermoset plastics have strong, permanent bonds. These bonds keep thermoset polymers from ever melting again, cultivating a high heat tolerance.

Think about this phenomenon like an egg. When you break an egg into a frying pan, the egg gradually cooks and loses its original viscosity. The heat works its way through the substance, solidifying a once liquid texture into a thoroughly concrete fried egg. After you cook the egg, you cannot return it to the liquid state. Thermoset polymers work in much the same way. After the initial heat treatment, you cannot re-melt the heat-resistant plastic.

Thermosets vs. Thermoplastics

There are two main types of plastic in the plastics industry with regards to their heat-related properties: thermosets and thermoplastics. Thermoset polymers have a high heat tolerance and withstand immense temperatures due to their heat treatment. Thermoplastics, on the other hand, melt when you apply heat. So, when you hold a flame up to a thermoset, the plastic will not move—in fact, it will harden further; but when you hold fire up to a thermoplastic, the substance will begin to melt and lose its form.

Thermosets and thermoplastics are variations of the same tune—they both consist of polymers with the single exception that thermoset polymers have those distinctive three-dimensional bonds. Thermoplastics lack this extra layer of connection, making it easy for the polymer chains to slide around one another and break apart under heat. These differences come full force with regards to the recyclability and application of each. But the simple reality is that thermoset polymers are the best plastic for any high-temperature or high-corrosion scenarios.

Thermoset Polymers and the Real World

It is one thing to understand the molecular bonds and chemistry behind thermoset polymers, and it is quite another to grasp their practical use. These are the real-world implications and applications of thermosets that you should know.

History of Thermoset Polymers

As with many modern inventions we take for granted, thermoset polymers began at the turn of the twentieth century. In the early 1900s, scientists invented the first thermoset: Bakelite. Though several plastics existed at this point, none had the unique properties of thermoset polymers. Once Bakelite appeared on the scene, thermosets filled needs in many industries requiring high-heat applications. Interestingly, people used Bakelite primarily in cookware and, later, in WWII weaponry once conflict broke out. Since then, thermosets boast a wide array of usages.

This broad applicability trend continues today, where thermosets are the low-cost and accessible material option for many manufacturers. Additionally, specific thermoset polymers are beginning to replace their metal counterparts because of their low thermal conductivity and resistance to corrosion and water. Take your car engine, for example. This machinery becomes quite hot after running for a while, and cars exist to weather all outdoor situations from rain to ice. Therefore, manufacturers must make your car with pieces that can withstand harsh temperatures and weather conditions.

Applications of Thermoset Polymers

You can find thermoset polymers in all sorts of places where heat and corrosion exist in force. The automotive, appliance, and electrical industries all find essential uses for thermosets that no other material can match. Thermoset plastics are present in car transmissions, appliance knobs, switch plates, and standoff insulators, to name a few. The value of thermosets lies in their hardness and moldability, offering a high strength-to-weight ratio.

Thermoset polymers vary in material composition and shape, which affects how people apply them. Take our fiberglass-reinforced thermoset polyester composite, thermalate, for instance. Our technicians at Red Seal Electric Company developed this material for injection molding, thermoforming, and press platen insulation, among other things. This asbestos-free part offers high compressive strength along with the other cornerstone characteristics of thermosets. If you have questions about our Thermalate H320 features, reach out to our team today.

Now that you have everything you need to know about thermoset polymers, figure out which plastic options best suit your industry. If you have questions about implementing plastic-based parts, contact our specialists at the Red Seal Electric Company to find the best match.