Elastomers are everywhere around us. We depend on them, probably more than we ever imagined. They’re in our cars, our houses, our offices, and everywhere else. And because of their wide usage, the elastomer market is estimated to be worth about 92.36 billion this year 2021.
In this piece, you’ll learn everything you need to know about what elastomers are (and what they aren’t), their categories, and common examples and applications of the billion-dollar polymers. Finally, you’ll see the most efficient way to ship your bulk elastomers.
What are Elastomers?
Elastomers are elastic polymers. In fact, the name “elastomer” was coined from “elastic polymer”. The intermolecular forces holding the molecules within elastomers are weak so that they can move apart from one another under strain. However, these weak intermolecular forces are not so weak that they break so easily under strain. Another unique characteristic of elastomers is that they are viscoelastic, meaning they are elastic and viscous.
How Are Elastomers Different From Polymers?
“Polymer” is a term that is so closely related to elastomers that some people wrongly use them interchangeably. Although these two are similar to a very large extent, some differences set them apart without ambiguity.
A major similarity is that elastomers are a category of polymers. This similarity is very important to note, as elastomers still possess some properties that are peculiar to all polymers. However, an elastomer differs from other categories of polymers in its:
● Physical Properties
Many of the physical properties of the elastomer hinge on its elasticity. For instance, the extremely high resistance of elastomers is mainly because of their elasticity. Polymers, on the other hand, have various physical properties, depending on the category. Remove the elasticity property from polymers and what you have is just another easy-to-break polymer.
Elastomers are unique for their elasticity, and they can retain their shapes and sizes after deformation. Many other polymers, on the other hand, have a brittleness, rigidity, or hardness that may lead them to permanent deformation at the application of force.
Elastomers are amorphous, meaning the molecules of elastomers don’t have a definite shape. This amorphous nature makes them well-suited for applications where flexibility is required. Other polymers range from being amorphous to being crystalline in their molecules.
Categories of Elastomers
Elastomers fall into two major categories, depending on how they react under the sulfur vulcanization process. The first is the saturated elastomer category while the other is the unsaturated elastomer category.
The sulfur vulcanization process involves the heating of natural rubber or other related polymers with accelerators and curatives based on sulfur. This curing process aims to derive varying degrees of hardness, mechanical durability, and elasticity from the polymers.
1. Saturated Elastomers
Saturated elastomers resist sulfur vulcanization. They aren’t very reactive, so they have strong stability under exposure to heat, ozone, radiation, and oxygen. Examples of saturated elastomers are:
- Ethylene propylene diene rubber (EPDM)
- Ethylene propylene rubber (EPM)
- Epichlorohydrin rubber (ECO)
- Fluorosilicone rubber (FVMQ)
- Chlorosulfonated polyethylene (CSM, or Hypalon), and many more.
2. Unsaturated Elastomers
Sulfur vulcanization can cure unsaturated elastomers. And this explains why unsaturated elastomers have more areas of applications than saturated elastomers because their properties can be modified to suit various purposes through sulfur vulcanization. Examples of unsaturated elastomers are:
- Butyl rubber
- Natural polyisoprene
- Synthetic polyisoprene
- Styrene-butadiene rubber
- Chloroprene rubber
- Nitrile rubber, and many more.
Common Elastomers and their Uses
Here are some of the most commonly used elastomers, their strengths, weaknesses, and their applications:
Butyl is made of mostly polyisobutylene (98%) and a bit of isoprene (2%). What makes it suitable for most of the applications we use it for are its great air retention, flexibility, and gas repellence.
The advantages of butyl elastomer include:
- Impressive impermeability to gas and moisture.
- Significant resistance to factors that could lead to its degradation or the degradation of whatever it protects. Examples of these invading factors include sunlight, heat aging, ozone, silicone fluids, oils (animal or vegetable), and many more.
- Excellent at energy absorption, and as a result, having a high electrical insulation performance.
- Oxygenated solvents, flexing, abrasion, and flexing don’t get through to it.
The limitations of butyl rubber include are these:
- It could prove tricky to handle during processing, as it has it tends to blister, creep, or trap air.
- Aromatic and aliphatic hydrocarbons are its undoing. It has low resistance levels to them. Other chemicals it’s weak against include coal, diesel-based lubricants, and tar.
Applications of butyl rubber
Some applications of butyl rubber are these:
- Butyl rubber is excellent for use in seals and vacuums because of its gas resistance.
- Tire inner tubes and liners are often made of butyl rubber.
Despite sharing a similar look and feel with natural rubber, silicone is in a class of its own among elastomers when it comes to molecular structure. While other elastomers have carbon and hydrogen atoms in their structures, silicone has silicon and oxygen. As a result, it is very flexible. It also remains stable to a very large extent under exposure to a wider range of temperatures. On the downside, however, its chain is weak.
Silicone has the following advantages:
- Silicone beats other elastomers in applications that involve exposure to a wide range of temperatures.
- The elastomer exhibits significant resistance to elongation, fatigue, ozone, UV rays, oxygen, fungus, and moisture.
Silicone has the following disadvantages:
- Silicone exhibits low resistance to concentrated solvents, oils, hydrocarbons, steam, concentrated acids, and some more.
- Tensile, abrasion, and tear resistance are not the strong suits of silicone.
Applications of silicon
Silicone has the following applications:
- It is used in products like seals, bellows, gaskets, and o-rings.
- Silicone is well suited for applications in extreme temperatures.
When neoprene was first produced, it was meant to serve as a synthetic replacement for natural rubber. Today, it not only serves as an alternative to natural rubber, but it also finds purpose in vast areas of application where natural rubber can’t be used.
Some pros of neoprene are these:
- Neoprene is a very versatile rubber.
- Some compounds that contain neoprene are flame retardants. This spares a manufacturer some expenses on flame retardant polymer additives.
- Exceptional mechanical properties, such as abrasion strength and resilience
- Neoprene has applications in both metal and fabric products.
- Great resistance to the weather, oils, solvents, petroleum oils, refrigerants, oxidation, sunlight, ozone, and more.
Neoprene has the following cons:
- Neoprene is expensive.
- Exhibits poor resistance to nitro hydrocarbons, aromatic hydrocarbons, ketones, esters, and potent oxidizing acids.
- Neoprene may not be the best elastomer for some specific purposes, as many other elastomers have better properties.
Applications of neoprene
- Neoprene is often the main rubber for situations where the seal is exposed to silicate ester lubricants, and weathering refrigerants.
- Used in gaskets and seals, weather stripping, engine coolants, motor mounts, refrigeration seals, and a lot more.
Ethylene-Propylene-Diene Modified (EPDM)
The two types of EP rubber you’ll find around are EPDM and EP. EPDM is an unsaturated elastomer that responds well to sulfur vulcanization curing. EP, on the other hand, is cured with peroxide.
The strengths of EPDM include:
- Remarkable resistance to UV exposure, ozone, water (steam or liquid), heat, and weather aging, steam, vegetable and animal oils, oxygenated solvents, brake fluids, and many more.
The weaknesses of EPDM rubber are the following:
- It is not recommended that you use EPDM rubber with petroleum oils, solvents, or fluids, as this could lead to the swelling of the material.
- It also has less than average resistance to aliphatic and aromatic hydrocarbons.
Applications of EPDM rubber
Some of the applications of EPDM include:
- In most outdoor applications where exceptional water and weather resistance is required of the rubber, EPDM is up to it.
- Manufacturers use EPDM in making bumpers, gaskets, auto-braking systems, conveyor belts, dust covers, and many more
Although the Hevea Brasiliensis tree is one of the major sources of natural rubber, you can also get this elastomer in its raw form from the juices of a lot of trees, vines, and shrubs. The remarkable mechanical properties of natural rubber are its greatest strength.
The advantages of natural rubber include:
- Top-notch mechanical properties, such as impressive tensile, tear resistance, electrical insulation, and elongation.
- The low compression set of rubber means it allows for bonding with many other materials.
- The abrasion resistance of natural rubber only gets better when it bonds with carbon black.
- Even under low temperatures, natural rubber still maintains its flexibility
Some of the disadvantages of natural rubber include:
- Natural rubber needs polymer additives to help it gain resistance against sunlight, ozone, heat, and oxygen.
- The degradation of natural rubber is accelerated when it is exposed to solvents, hydraulic fluids, oils, and petroleum derivatives.
Applications of natural rubber
Some common uses of natural rubber include:
- Natural rubber finds itself in various products, including metal and fabric, because of its ability to bond with a wide array of materials.
- Tires, tubings, seals, hoses, electrical components, drive wheels, vibration isolators, and many others involve the use of natural rubber.
Styrene-Butadiene Rubber (SBR)
The primary purpose of SBR was to serve as an alternative to natural rubber in the manufacture of tires. Today, it joins natural rubber as one of the most used elastomers in the world.
Some of the benefits of SBR are:
- SBR bonds excellently with many other compounds to offer a wide variety of properties for various applications.
- Excellent electrical insulation.
- Impressive resistance to oxygenated solvent, alcohol, and mild acid.
- Better than natural rubber in water resistance, flexibility in low temperatures, heat aging performance, heat resistance, and abrasion resistance.
The disbenefits of SBR are:
- It has low resistance to many hydrocarbons, hydraulic fluids, oils, fluids, strong acids, and greases.
- It also requires polymer additives to supply it with some crucial properties, such as sunlight, ozone, and oxygen resistance.
Applications of SBR
Uses of SBR include:
- Products like hoses, gaskets, tubes, tires, shock mounts, lining rubber, and conveyor belt covers use SBR.
Nitrile is most popular for its oil resistance. It is made from acrylonitrile and butadiene.
The strengths of nitrile include:
- Nitrile exhibits great resistance to heat aging, a wide range of aromatic hydrocarbons, gasoline, solvents, hydraulic fluid, vegetable oils, mineral oils, many acids and bases, and ozone.
- As it has excellent oil resistance, some of the best uses of nitrile are in areas that are exposed to oil and grease.
- When you combine nitrile with some materials, you can get impressive abrasion and tear resistance from it.
The weaknesses of nitrile are:
- It has low resistance to nitro hydrocarbons, chlorinated hydrocarbons, and ketones.
- Nitrile, on its own, has poor sunlight, oxygen, and ozone resistance. It depends on polymer additives to achieve these.
- Not suitable for electrical insulation applications.
Applications of Nitrile
The common uses of nitrile include:
- Sealing products mostly have nitrile in them. The reason for this is nitrile’s high resistance to grease, petroleum, and gasoline.
- Alcohol and hydraulic fluid applications involve the use of nitrile.
- Nitrile is available in commercial-grade blends that can be deployed in applications that aren’t very demanding.
- Many automotive products often make use of nitrile. Examples of such products include rollers, shock mounts, petroleum oil seals, grommets, hydraulic hoses and fluid seals, oil handling hoses, and many more.
Here is a great video by Star Thermoplastics, Alloys and Rubbers explaining the uses and process of manufacturing Elastomers.
Shipping Your Bulk Elastomers with Total Connection
The transport of elastomers is just as important as the polymers themselves. And that is why extra care should be given to the proper shipping of these materials. And with some elastomers being classified as hazardous materials, paying full attention to shipping them properly becomes a compulsion.
At Total Connection Logistics services, we handle the transport of all kinds of elastomers and other substances in bulk. We rely on the affordability of our services, our expertise, and our flexibility to push your supply chain to its best. Be a part of our logistic efficient logistic network by filling out the quote form below.