It is very hard for a person to get through their day to day life without interacting with rubber in some way. Rubber is used in the manufacture of thousands of different products; everything from tires and the soles of shoes, to spatulas and basketballs. Most people start using rubber products at a very early age; from the rubber bands that hold things together to the rubber erasers on pencils that correct mistakes in our first attempts at writing.
Rubber is one of the most versatile materials in the world. A look at your car’s interior, or engine, transmission, and braking system will reveal many different rubber products. Rubber is used as roofing, flooring, and siding on some houses; it has gone down to the bottom of the ocean and up to the moon and beyond; and has helped keep infants quiet and the aged remain mobile.
Around 35 to 40 billion pounds of rubber is produced worldwide every year. About 30 percent of this is natural rubber which is usually extracted from the Para rubber tree and some other natural sources, while 70% are manmade, synthetic and sometimes specialized rubbers.
Although natural rubber has been around in one form or another for centuries, synthetic rubbers were only invented in the late 19th century, and really came into their own during the Second World War, when all sides in that conflict found themselves facing shortages of the real thing. Synthetic rubbers are usually polymer elastomers manufactured largely from petroleum waste and byproducts. These polymers mimic the elasticity, waterproofing, and other qualities of natural rubber – often surpassing the original in some properties.
Both natural and synthetic rubbers are often subject to vulcanization during their manufacture. Invented by Charles Goodyear in the mid-1850s, vulcanization is a process in which chemicals (often sulfur or metal oxides) and heat are applied to rubber to harden it, and increase its elasticity and durability.
Other more sophisticated processes are sometimes applied to certain types of synthetic rubbers, depending on their specific purpose. Different types of synthetic rubbers can fill overlapping needs, and so they are often interchangeable.
The word ‘rubber’ is actually a catch-all term that is used to describe a number of different materials. So what are the different types of rubber that are commonly used today?
Although it did not acquire its current name until the 1700s (when a British scientist observed that the material was good at ‘rubbing’ away pencil writing from paper) natural rubber has been used for thousands of years. The first known use of the material dates back to before 1000 BC when the Incas, Aztecs, and Olmecs used it for making balls for games, durable containers, and waterproofing other items.
Also sometimes referred to as India rubber or gum rubber, natural rubber is the only non-synthetic type of rubber in common use today, and is usually sourced from the latex found in the Hevea brasiliensis plant, commonly referred to as the Para rubber tree. Often cultivated on large plantations covering hundreds of acres, the latex is extracted by ‘tapping’ the tree and allowing the liquid latex therein to drain into collection containers. When done properly, the tapping process (akin to how sap is extracted from maple trees for the production of maple syrup) will allow a healthy tree to produce latex for 20 to 25 years.
Most of today’s natural rubber (over 90%) is produced in Southeast Asia. Along with the Para rubber tree, some inferior grades of latex and other rubber-like substances can be sourced from dandelions, the vines of the Congo rubber plant, and the guayule plant – which is used extensively in the production of products for use by individuals who are allergic to natural latex.
Natural rubber is known for its durability, resistance to heat and cold, elasticity, flexibility, and resistance to tearing, degrading, abrasions, changes in climate, and surface friction (this is particularly important in the manufacturing of tires).
After processing (which usually involves some type of vulcanization) natural rubber is one of the most adaptable materials around and is used in the manufacture of a plethora of items including tires, gloves, some types of foam rubber, boots, flooring and roofing, hoses, balls, coatings for waterproofing, and insulation (usually for electrical and other types of wiring) – the list of uses goes into the thousands. Non-vulcanized natural rubber is also used in the manufacture of adhesives, including rubber cement.
Although it has been overtaken by its synthetic cousins since the 1960s because of cost and other factors, natural rubber is still one of the most widely used naturally occurring substances on earth and looks to remain a valuable resource for the foreseeable future.
First commercially marketed in the 1940s, silicone rubber (also referred to as polysiloxane) is used in both industrial and commercial applications. Highly resistant to temperature extremes as well as ultraviolet rays, ozone, and fire, silicone is a basically inert substance that does not tend to have a reaction when interacting with most chemicals. Silicone is manufactured in a large range of colors, can be easily formed into different shapes, and is available as both hard and liquid products.
Silicone is one of the most versatile of the synthetic rubbers and is used in the manufacture of hundreds of products ranging from the television remote controls and computer keyboards to shoes, clothing, and specialty tapes (often used in the aviation and aerospace industries).
Silicone is also widely used in automotive and home maintenance as a lubricant or sealant, often available in spray cans and tubes in its liquid and semi-liquid forms.
Because of its inert nature, silicone is one of the few synthetic rubber products that is both hypoallergenic and biocompatible and is widely utilized in the manufacture of medical equipment including respiratory masks, surgical gloves, IV tubing, syringes and many kinds of medical implants. It is also often used in the manufacture of food storage products, baby care items, cosmetics applicators, and cooking utensils.
Silicon is among the more expensive synthetic rubber products available, and as a result, has been phased out and replaced by other synthetics in most heavy industrial applications.
Polyurethane rubber was first produced by scientists at the I.G. Farben Company as a part of Nazi Germany’s quest to produce a synthetic rubber to make tires for military use during the Second World War. Because of its high flammability in its most basic form, however, these efforts were quickly abandoned. Its initial use was as an aircraft coating.
Today, the vast majority of polyurethane rubber (over 75%) is produced in the form of flexible and rigid foams with a wide range of densities and stiffness; these foams are often covered with other materials. The most flexible of these foams are often referred to as foam rubber. Between five and six billion pounds of polyurethane foam is produced annually.
Depending on how they are produced (and what is added to them) flexible polyurethane foams are usually very easy to mold into virtually any shape, and can often be cut with a simple pair of hand scissors. It is used in the manufacture of furniture cushions, bedding and pillows, and car and truck seats, armrests, and dashboards. It is also used in durable cleaning products (sponges and mop-heads), apparel and footwear, crafts, and as the underlayment in carpeting.
Solid polyurethane foam is used as interior insulation in refrigerators and freezers, and in the production of surfboards and body-boards, boat hulls and decks, pool floats, and buoys. It is increasingly being used as a replacement for some natural rubber gaskets in the automobile industry.
Non-foam types of polyurethane rubber are used in the manufacture of rubber rafts, construction sealants, packaging, and in the production of electronics. Polyurethane is used in the production of polyester clothing and as a spray-in or fabric-like insulation product in home construction. It is also used as an underlayment for various types of roofing.
In its liquid form, polyurethane is widely used as a varnish and sealant on both interior wood flooring and walls, and exterior decking. Polyurethane is also used in the manufacture of some epoxies.
Developed in 1941, nitrile rubber (also often called Buna-N or NBR) was among the first oil-resistant synthetic rubbers manufactured. Among its other properties, nitrile is resistant to heat and gas permeability. Along with commercial applications, nitrile is also used to make a number of industry-specific items.
Available as solid, flexible and foam products, nitrile has many specialized applications in the automotive industry due to its resistance to oil and other petroleum products. Nitrile is widely used as gaskets, o-rings, oil seals, and heavy-duty hoses in automobile and truck engines, as well as for belts, seals and hoses in the transmission and air conditioning systems.
Nitrile has also been used in the aviation and aerospace industries for the construction of self-sealing fuel tanks and bladders since the end of the Second World War. Due to its durability and resistance to tearing, heat and gases, it is also widely used for making the heavy-duty protective gloves used at nuclear power plants and in some heavy industry.
Nitrile’s commercial applications include its use in the manufacture of various molded goods, floor mats, footwear, and sponges. It is also used for inner tubes and some inflatable balls. As it is a sturdier material than natural rubber or silicone and is less likely to cause allergic reactions, many types of gloves are made of nitrile, including examination and lab gloves in the medical world, and those used for industrial and home cleaning.
In its liquid and semi-liquid forms, nitrile is also quite popular in the manufacture of sealants and adhesive products.
EPDM (Ethylene Propylene Diene Monomer) rubber is a synthetic rubber compound widely used in the production of seals, hoses and tubing, and in the roofing industry. EPDM rubber is particularly good at dealing with both heat and cold, is widely used as a waterproofing agent, and as an insulator in electrical wiring.
EPDM is often used as seals (door, window, trunk, etc.) in the automotive industry, because of both its insulating and noise-reduction qualities. It is also used in the cooling and brake systems in cars and trucks, as well as the seal on refrigerator and freezer doors.
Because EPDM offers excellent resistance to both heat and cold, it is frequently used in the construction of flat roofs, and as a waterproofing sealant for pitched roofs. It is also used in many other outdoor applications, including garage door seals, outdoor furniture, and hoses.
While EPDM rubber provides excellent resistance to many of the things that can damage other types of rubber, it is not used in applications where it would come into contact with petroleum-based oils or fuels, mineral oils, and certain types of lubricants as it cannot stand up to these.
Dating back to the 1930s, chloroprene is one of the older synthetic rubbers in use today. Almost universally referred to by its registered DuPont trademark name Neoprene, this is one of the most versatile synthetic rubbers on the market today and has a large number of uses. Neoprene is known for its flexibility, waterproofing, and insulating properties, and is used in both industrial and commercial applications.
Neoprene is less susceptible to degrading, corrosion, and burning than most other synthetic and natural rubbers, making it excellent as a base for corrosion-resistant coatings, high-pressure gaskets, belts, hoses, and certain types of adhesives. It is also used to make the weather stripping used on emergency exits and fire doors, as well as in the manufacture of Halloween, military and industrial safety masks.
Neoprene is very popular in the manufacture of aquatic clothing, gear, and equipment. Because it has both waterproofing and insulating qualities, it is widely used for wetsuits for swimmers and divers, and hip waders for fishermen. It is also sometimes used for snorkels, diving masks, and oxygen tank mouthpieces.
Other commercial applications for Neoprene include drum practice pads, laptop computer sleeves, mouse pads, remote controls, and dishwashing gloves (particularly for those allergic to latex). It is also used in hydroponic gardening equipment to stop the growth of algae, roof coatings and membranes, wheelchair harnesses and accessories, orthopedic knee and wrist braces, and as the lining for landfills to help retard fires.
FKM (also known as fluorocarbon rubber) is often referred to by its widely used brand name Viton, a registered trademark of the Chemours chemical company. FKM can often be recognized by its green or brownish color, and is one of the densest of all synthetic rubbers. Although widely used in the manufacture of certain items, FKM is considered something of a specialty rubber.
FKM is particularly resistant to mineral and synthetic oils, petroleum fuels and other products, lubricants, most hydrocarbons, and organic solvents. It is most often utilized in the manufacture of many different types of o-rings including those used in cars and trucks (particularly those that run on diesel and biodiesel fuel, as a replacement for the weaker nitrile o-rings), PVC tubing and couplings, and in scuba diving equipment.
FKM is also used in some automotive hoses and gaskets, as well as float valves in diesel-engine carburetors. It is also often used as a substitute for nitrile rubber in the manufacture of protective gloves, especially in industries that use particularly strong organic solvents or unrefined petroleum products.
SBR (also known as styrene-butadiene rubber, or as the Goodyear registered trademark name Neolite) was developed in the late 1920s in Germany. Harder and more durable than many other synthetic rubbers, SBR has many of the same characters as natural rubber and was used extensively by the Allied and Axis forces during World War Two in the manufacture of automobile and truck tires and other rubber products.
One of the least expensive general purpose synthetic rubbers available, over five billion tons of SBR is produced annually. Because of its durability, and resistance to friction and tearing, it is still widely used in the tire industry; almost half of the pneumatic tires manufactured in the United States are made from SBR.
SBR is also used for making shoe soles and replacement heels, rubber cutting boards, and specialty gaskets such as those used in some drive-couplings and heat exchangers. It is also sometimes used as a seal in hydraulic braking systems, due to it being highly resistant to hydraulic brake fluids.
A liquid form of SBR is used in the production of some coated paper products as a binder and was once used in making chewing gum. It is also sometimes used in the construction industry as a sealant and waterproofing agent, particularly in basements and substructures.
Created in 1937 by scientists at Standard Oil of New Jersey, Butyl (sometimes called isobutylene isoprene) is one of the most gas-impermeable, airtight synthetic rubbers available, as well as one of the most versatile.
Due to its airtight qualities, butyl rubber is widely used in the manufacture of inner tubes as well as air-filled balls (soccer, footballs, basketballs, etc.), inflatable rubber rafts, home window insulation, and as an interior sealant in car and truck tires. It is also used in the manufacture of industrial and home cleaning equipment such as chemical resistant gloves.
In its liquid form, butyl is often found in diesel and petroleum fuel additives where it acts as a detergent that helps keep fuel injectors clean and eliminate engine knock. It will often be found in products used for cleaning up oil spills, particularly in the water. It is also used as a binder in C4 and some other types of plastic explosives, in gas masks, in waterproof tapes, like a rubber roof sealant, and as stoppers in medicine bottles.
Food-quality butyl has been used as the base for most chewing gum since the 1950s.
Santoprene is a thermoplastic vulcanizate (TPV) rubber and one of the more recently developed types of synthetic rubbers. Commercially available since the early 1980s, Santoprene is a registered trademarked product of ExxonMobil Corporation. Santoprene is a specialty rubber and designed for specific applications.
Lighter weight than most synthetic rubbers, Santoprene is a derivative of EPDM rubber. It is a highly vulcanized product and resistant to extreme temperatures and weather conditions, many chemicals, air and water penetration, and electricity.
Santoprene is widely used in the automotive industry for weather sealing doors, hoods and trunks, and in the manufacture of air ducts, cable insulation, lightweight engine parts, and bumpers.
In construction, Santoprene can be found in glazing seals (particularly on windows and doors), the decks of bridges and parking lots, and sewage pipes. It is also often used as insulation for high voltage power lines and couplings.
The door seals for many makes of home appliances including refrigerators and freezers, dishwashers, and washing machines are made of Santoprene. It is also used in tool manufacturing.
ACM, also often called acrylic rubber, is another specialized synthetic rubber. It provides excellent resistance to ozone and heated oils and is not prone to oxidation.
The vast majority of ACM rubber products are used in the automotive industry, particularly in the transmission system due to its exceptional resistance to heat and transmission fluids. Products include transmission bushings, o-rings, hoses, belts, seals and gaskets.
ACM is also sometimes used in the manufacture of some industrial sealants and protective coatings.
Also called FVMQ, fluorosilicone sits at the upper end of synthetic rubbers cost-wise, and so is not widely used as a general purpose rubber and usually limited in its applications to specialized uses and products.
Fluorosilicone is suitable for use in temperatures ranging from -100 degrees F to over 350 degrees F. It is known for its resistance to hydraulic and transmission fluids, engine oils, synthetic lubricants, ozone, fire, and oxidation.
In large part, because it keeps its integrity so well in extreme temperatures, fluorosilicone is most often associated with the aerospace and aviation industries where it is used to produce o-rings, gaskets, seals, hose linings, and some engine parts. It is also used as seals, gaskets, and o-rings in some hydraulic equipment and engines.
FFKM (also called perfluoroelastomer) is a highly specialized synthetic rubber used to manufacture o-rings, gaskets, and sealants in industries in which they are likely to into contact with harsh chemicals and plasmas.
Resistant to over 1800 chemicals and compounds, products made of FFKM are most often found in the oil and gas, pharmaceutical, aviation, chemical processing, and nuclear power industries.
Lisa has a Bachelor’s of Science in Communication Arts. She is an experienced blogger who enjoys researching interesting facts, ideas, products, and other compelling concepts. In addition to writing, she likes photography and Photoshop.