(Almost) Everything You Need to Know About Synthetic Rubber

Posted By: Sperry & Rice
Monday June 27, 2022

Sperry & Rice has been in the rubber business since the 1940s and we might be a bit biased, but we believe that rubber is one of the most important substances on earth. Consider everything rubber is used for: protective gloves, balloons, roofing membranes, pencil erasers, wetsuits, boots and the soles of shoes, faucet washers, pond liners, lifeboats, bike tires and innertubes, insulation, and gaskets and seals for everything from car engines to washing machines.

And we can’t forget about tires. More than half of the supply of rubber goes into making tires for cars, trucks, buses, and airplanes.

Yes, rubber is important, and there are two types of rubber: natural and synthetic. Natural rubber is obtained from latex, a milky fluid found in about 2,500 species of plants. The biological function of why plants contain latex isn’t completely understood, but it helps plants heal damage and block the entry of harmful bacteria into the plants.

But this is all about synthetic rubber so let’s start with the basics.

What is synthetic rubber?

Synthetic Rubber is any artificial elastomer, a material that can undergo elastic deformation and return to its previous size without permanently altering its shape. Synthetic rubber can be used in place of natural rubber, and in many instances, is preferred because of improved and specialized elastomeric properties.

History of synthetic rubber

The search to create synthetic rubber dates to the late 1880s but took on new urgency with the beginning of World War II. A military airplane required a half ton of rubber; a tank needed one ton; and each person in the military required 32 pounds of rubber for boots, clothing, and equipment. Not to mention tires for tens of thousands of motorcycles, jeeps, and trucks, so the need for rubber far exceeded available supply.

To produce the rubber needed for the war, the U.S. government enlisted the help of rubber companies, the petrochemicals industry, and university research laboratories, and was able to increase the synthetic rubber industry from an annual production volume of 231 tons in all of 1941 to around 70,000 tons a month in 1945. (American Chemical Society)

Today, about 70% of rubber used in manufacturing is synthetic, and is a descendant of the synthetic rubber-styrene produced for World War II.

Types of synthetic rubber

There are about 20 types of chemicals that are used for making synthetic rubber varieties and each has individual properties and advantages; here are just a few synthetic rubber types:

Acrylic Rubber contains acrylonitrile and has good resistance to hot oil but poor resistance to water or moisture.
Butadiene Rubber (BR) is very elastic and is blended with natural rubber to produce tires.
Butyl Rubber (IIR) is very flexible and is available in different grades.
Chlorosulfonated Polyethylene (CSM)is used in hoses, seals, and gaskets, and in roofing membranes, and liners and covers for pools.
Ethylene propylene diene monomer (EPDM) is one of the most popular synthetic rubbers because it is durable and very resistant to heat, weather, and ozone aging while remaining flexible at high and low temperatures. EPDM is highly resistant to liquids such as water and acids and is commonly used as electrical filling and lamination and is also used in the automotive industry and construction plants.
Nitrile Rubber (NBR) is produced by polymerization of acrylonitrile with butadiene and is used to make thin rubber gloves.
Polychloroprene (CR) or neoprene is a synthetic rubber used in more than 15 industries because it maintains an ideal balance of mechanical strength and oil and chemical resistance. Other properties of neoprene include weather and aging resistance, low flammability, and the unique capability of bonding with other substrates. Neoprene is used to produce gloves, wetsuits, seat covers, cables, and conveyor belts.
Silicone Rubber (SiR) has high heat resistance and is used as an insulating material.
Styrene Butadiene Rubber (SBR) was originally developed in Germany in the early 1900s and has since become the most used synthetic rubber due to its processability, good abrasion, and good aging resistance. Styrene butadiene rubber can be polymerized in several ways which changes its consistency and allows it to be used for many different applications. SBR is most used in vehicle tires as well as industrial hoses, conveyor belts, shoes, gaskets, and molded or extruded rubber goods. It can also be used in building applications for sealing and binding.

Why is synthetic rubber so important?

For every application of rubber you see, there are 100 that you don’t see. Think about your car or truck. Of course, the tires are rubber, but so are its unseen hoses, belts, gaskets, weatherstripping, airbags, component covers and shrouds, pedal pads, o-rings, grommets, seals, and bushings.

Now, imagine how many times rubber is used in a building. Window and door seals, HVAC components, paints and sealants, expansion joints, roofing membranes, and anti-vibration mountings.

We are incredibly dependent on the use of both natural and synthetic rubber.

What makes synthetic rubber so vital is its wide variety of properties and ability to meet the requirements of many different industries:

Its remarkable elasticity and amazing resistance to water
Its strong resistance to alkalis as well as other acids that have weak properties
Its adhesiveness, toughness, impermeability, and its excellent resistance to electricity
It is also resistant to oxygen, oil, solvents, and various other chemicals
It doesn’t wear off easily
If exposed to high temperatures, its flexibility is not compromised
Bonds easily to metal
Easy to clean

What are the advantages to using synthetic rubber?

As mentioned above, thanks to the variety of synthetic rubber formulations available, it can be made to withstand any conditions required of it, from hot to cold, acidic to alkaline, and everything in between. Synthetic rubber is resistant to solvents, oxygen, oils, and other chemicals which allow it a longer life, and it doesn’t lose its flexibility when exposed to wide range of weather conditions.

What is synthetic rubber used for (besides tires?)

Synthetic rubber is used in everything from adhesives to latex gloves. Slightly harder, more durable, and less elastic synthetic rubber is used to make aircraft tires, hose pipes, and waterproof gaskets.

By industry, here is a breakdown of how synthetic rubber is used:

The Transportation industry is the largest user of rubber – for tires, obviously
The Construction industry uses synthetic rubber in elevator belts, hoses, tubes and seismic bearings
The Consumer Products industry uses rubber in footwear, erasers, and sporting goods The Medical industry uses synthetic rubber to make surgical gloves, contraceptives, and catheters

Rubber is an amazing material, and synthetic rubber comes in many types and shapes, with wide and varied properties. Sperry & Rice has been in the rubber business more than 70 years and offers innovative engineering, advanced manufacturing processes, and comprehensive quality controls to produce precision extruded synthetic rubber components for the HVAC, automotive, transportation, and appliance industries. Our reputation lies in making sure that the rubber we provide makes the finished products of our clients reliable, and of the highest quality.

For more information about how Sperry & Rice can be your custom extruded rubber partner, Contact Us!

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