There are two main types of rubber available: natural and synthetic. Each retains exhibits physical and chemical properties that differentiates them from each other. Natural elastomers are derived from the latex sap of the rubber tree. On the other hand, synthetic types of rubber are made through monomers derived from petroleum oil and its byproducts. While there is only one type of natural rubber, there are multiple types of synthetic rubber. Additionally, due to the petrochemicals used to create synthetic rubbers, they will be more durable than natural rubber. Despite the differences in material makeup and physical and chemical properties, both natural and synthetic types of rubber are elastomers, allowing things like elastomer sheets to provide a degree of flexibility and pliability that makes them widely useful. In this article, we’ll answer your most burning questions about rubber, including:

• What are two rubber types?
• What is the most flexible rubber sheet?
• What is the most durable rubber sheet?
• What is the cheapest type of rubber?
• How many types of synthetic rubber are there?
• What type of material is silicone?
• What material is similar to silicone?
• Is silicone stronger than rubber?
• Is elastomer the same as silicone?
• What is the material of rubber sheets?
• How is natural rubber harvested?

1. What Are Two Rubber Types?

The two main types of rubber are natural rubber and synthetic rubber. The main difference between the two types of rubber is their material compositions, which affects their physical and chemical properties. Synthetic rubbers are man-made types of rubber made from petroleum-based chemicals which give them enhanced properties when compared to the properties of natural rubber. Natural elastomers are environmentally-friendly and plant-based types of rubber that are derived from Hevea brasiliensis, or the rubber tree. It retains excellent properties, such as a high tensile-strength, abrasion-resistance, and a low compression set; however, according to one authority, natural rubber “has only moderate resistance to damage from exposure to heat, light and the ozone in the air.” Because of this, natural elastomers are not as durable as the types of synthetic rubber that have become prominent in today’s market. According to the same source, synthetic rubber “offers better resistance to abrasion than natural rubber, as well as superior resistance to heat and the effects of aging. Many types of synthetic rubber are flame-resistant, so it can be used as insulation for electrical devices.” Despite their differences in properties, both natural and synthetic rubbers are extremely strong materials.

What Is the Most Flexible Rubber Sheet?

All types of rubber are flexible, but there is no one rubber that is the most flexible, as factors such as durometer and gauge thickness affect rubber’s flexibility. The lower the durometer of a rubber product the more flexible it is. And of course, thinner sheets of rubber will show more flexibility than their thicker counterparts. As elastomers, all types of rubber, whether natural or synthetic, are highly elastic and flexible: Flexible rubber sheets are the standard. According to Britannica, an elastomer is “any rubbery material composed of long chainlike molecules, or polymers, that are capable of recovering their original shape after being stretched to great extents—hence the name elastomer, from ‘elastic polymer’.” As elastomers, natural and synthetic rubbers display a degree of flexibility and pliability regardless of what their durometer ratings are—whether it be 60- or 90-durometer rubber. But, their specific durometer ratings will determine the material’s hardness and, therefore, their level of flexibility. While the level of hardness of the material is one factor that affects rubber’s flexibility, another factor that affects its flexibility is its thickness. When it comes to a rubber sheet, thin-ness matters. The thinner the thin sheet rubber is, the more pliable it will be, making it easier to bend. As elastomers, both synthetic and natural elastomers will be flexible to some degree. Degrees of hardness and levels of thickness—augmentable traits—affect how flexible a rubber item is. Thus, when it comes to a rubber sheet, density, as well as thickness, is something that affects its level of flexibility. A soft elastomer sheet (perhaps a 1-mm-thick rubber sheet) is more flexible than, say, an elastic rubber sheet that is 1-inch-thick rubber.

What Is the Most Durable Rubber Sheet?

There is no most durable rubber, but how durable a rubber material is depends on its properties. However, synthetic rubbers tend to be more durable than natural rubbers since the chemical compounds used to create synthetic rubbers bring so many advantages to the table. Natural rubber, although highly impact- and abrasion-resistant, typically falters in the face of harsh environmental factors, high temperatures, and caustic chemicals—especially when compared to synthetic types of rubber. For example, due to natural rubber’s organic carbon-to-carbon-bonded backbone structure, it is susceptible to damage from exposure to ozone. In addition, although natural rubber is resistant to most acids, salts, ammonia, and alkali chemicals—caustic solvents, such as bleach, oils, and greases, can deteriorate the material. Natural rubber also has a lower melting point of approximately 356 degrees Fahrenheit. In contrast, a synthetic rubber sheet is much more chemically, thermally, and environmentally stable than a natural rubber sheet. For instance, synthetic rubber, such as silicone, has an operating temperature range of -212 to +572 degrees Fahrenheit. The petroleum-based monomers used to create synthetic types of rubber are invaluable in bolstering these materials’ traits. According to a library associated with the University of California, synthetic rubbers are created through the polymerization of “isoprene (2-methyl-1, 3-butadiene), 1, 3-butadiene, and chloroprene (2-chloro-1, 3-butadiene).” In this process, the polymerization of these compounds does not produce a carbon-to-carbon polymer backbone (the backbone structure found in natural elastomers), allowing synthetic rubbers to resist the degradation that natural rubber experiences when faced with damaging environmental factors, such as UV-rays, ozone, oxygen, and moisture.

What Is the Cheapest Type of Rubber? 

Post-consumer types of rubber, such as recycled and reclaimed rubbers, are the cheapest types of rubber because of the reduced costs it takes to create these materials. When it comes to rubber sheets, price depends in part upon the materials used to make the elastomeric sheet. Both recycled and reclaimed rubber materials are sourced from discarded car tires which makes them environmentally-friendly materials—perfect for cheap rubber sheets. By using non-biodegradable rubber to make new products, recycled and reclaimed rubbers reduce the amount of rubber waste that ends up in landfills. These are cost-effective types of rubber because they do not require as much effort to produce when compared to other natural and synthetic rubbers. According to Wikipedia, “scrap tires as a back-fill and cover material are also more cost-effective, since tires can be shredded on-site instead of hauling in other fill materials.” Not only does the usage of old vehicle tires make these rubber variations an eco-friendly and cost-effective material choice, but it also makes for durable rubber materials. Case in point, according to ScienceDirect, “generally, utilization of WTR [Waste Tire Rubber] as a filler for polymer composites noticeably reduces materials costs, while suitable modification/functionalization of WTR may significantly enhance the performance of plastics and rubbers.” Recycled and reclaimed types of rubber, though the cheapest rubber materials, are also highly durable and outdoor-friendly materials. If you’re looking for a cheap rubber sheet, recycled and reclaimed rubber materials are great options.

How Many Types of Synthetic Rubber Are There?

There are many types of synthetic rubber, including silicone, EPDM, SBR, nitrile, neoprene, and thermoplastic rubbers such as Santoprene. The first synthetic types of rubber were invented to be a stronger alternative to natural rubber, allowing them to provide better physical and chemical properties. One of the main differences between synthetic and natural rubbers is their resistances to environmental variables. Synthetic rubbers will not be damaged when exposed to harsh outdoor conditions, such as UV-rays, ozone, oxygen, and moisture. Natural rubber, although moisture-resistant, becomes damaged when exposed to ozone—this phenomenon is called “ozone cracking,” when the material cracks and breaks. Each synthetic rubber offers its own unique properties that are ideal for certain applications. For instance, silicone rubber is known for its superior thermal stability—it can withstand extremely high temperatures without melting and extremely low temperature without becoming brittle. On the other hand, nitrile rubber is highly resistant to greases and oils, substances which can severely damage natural rubber.

2. What Type of Material is Silicone?

Silicone is a synthetic rubber material characterized by its ability to withstand high temperatures—it can operate within temperatures of up to 500 degrees Fahrenheit. Unlike natural rubber, silicone is an inorganic polymer, which means that it has a unique silicon-to-oxygen-bonded polymer backbone structure. This structure gives it superior temperature-resistance properties when compared to both natural and other synthetic types of rubber. Due to its unique molecular structure, a silicone synthetic rubber sheet is superlatively temperature- and chemical-resistant. In addition, thanks to its thermal stability, a silicone synthetic rubber sheet still remains flexible at low temperatures—other varieties of rubber tend to become hard and brittle in such environments. According to Wikipedia, “some properties such as elongation, creep, cyclic flexing, tear strength, compression set, dielectric strength (at high voltage), thermal conductivity, fire resistance and in some cases tensile strength can be—at extreme temperatures—far superior to organic rubbers in general.” Silicone rubber is available in three different grades: commercial, premium, and FDA. With three different types of silicone rubber, it is a very versatile rubber material. In some cases, it’s even used in applications that handle pharmaceuticals and foodstuffs.

What Material Is Similar to Silicone?

Thermoplastic rubber materials, such as Santoprene, are similar to silicone in that they can handle extreme temperatures. A thermoplastic sheet is composed of both plastic and rubber materials. According to the Standard Method for Determining Continuous Upper Temperature Resistance of Elastomers, a thermoplastic sheet holds up well against fluctuating temperatures as high as 300 degrees Fahrenheit and continuous temperatures as high as 275 degrees Fahrenheit. According to Omnexus, due to thermoplastic elastomers’ high temperature resistance properties, “TPE is considered as an efficient and cost-effective alternative for latex, silicone rubber, and polyvinyl chloride (PVC) compounds.” Thermoplastic materials are similar to silicone in that they retain the elasticity of elastomers while also being more heat resistant than most natural and synthetic rubbers.

Is Silicone Stronger than Rubber?

Silicone is stronger than other types of rubber in that silicone is generally better at withstanding heat and weather conditions. Natural types of rubber are considered “organic polymers” due to their carbon-to-carbon backbones. This makes natural rubber more susceptible to damage caused by damaging environmental factors and extreme temperatures. Although most synthetic types of rubber are capable of withstanding these damaging factors, they are generally not as strong as silicone. Silicone rubber has a silicon-to-oxygen backbone, a molecular structure that gives it better heat-resistance, chemical-resistance, insulation, and abrasion-resistance. Silicone has an extremely wide operating temperature range of -103 to 500 degrees Fahrenheit. Silicone products are also highly chemically-resistant materials. They are even used in applications where they are exposed to caustic chemicals, such as acetic acids, ammonia gas, and sodium sulfate. Silicone rubber remains flexible in low temperatures and is largely impervious to embrittlement—qualities with which natural rubber cannot compete.

Is Elastomer the Same as Silicone? 

Elastomer is the same as silicone because silicone is an elastomer. According to Britannica, an elastomer is “any rubbery material composed of long chainlike molecules, or polymers, that are capable of recovering their original shape after being stretched to great extents.” Both natural and synthetic types of rubber are elastomers and will offer a certain degree of flexibility—a level of flexibility which changes according to variables like hardness. Silicone is a synthetic elastomer known for its wide operating-temperature range, as it remains flexible through a wide range of high and low temperatures. Silicone can withstand temperatures from as low as -103 degrees Fahrenheit to as high as +500 degrees Fahrenheit. Even at temperatures as low as -103 degrees Fahrenheit, silicone will remain flexible and will resist cracking caused by embrittlement.

3. What Is the Material of Rubber Sheets? 

Natural latex sap is the material of natural rubber sheets, and petroleum-derived compounds are the raw materials for synthetic rubbers. Natural elastomers are organic materials that are harvested from the rubber tree. The latex sap harvested from this tree is then put through a production process in which the sap is combined strengthening agents. Consequently, natural elastomers are environmentally-friendly and biodegradable materials. The main raw material used to make synthetic types of rubber is a derivative of petroleum oil. This gives synthetic rubber physical and chemical properties that are stronger compared to those of natural elastomers. Case in point, according to EnvironmentalPolution, “[synthetic rubbers] are ‘tailored’ to provide particular properties such as oil resistance, flexibility at extremes of temperature, resistance to ozone, etc., and therefore cannot be regarded as capable of replacement by natural rubbers although in some respects synthetics can be used in place of natural.” This makes synthetic types of rubber nonbiodegradable yet physically- and chemically-stronger than natural elastomers.

How Is Natural Rubber Harvested?

This is how natural rubber harvested: Latex sap is extracted from the rubber tree and put through a solidifying process to create a solid material. This tree is known as Hevea brasiliensis. Latex is harvested through a process called “tapping”. Tapping is not harmful to the rubber tree, as angled cuts are intricately and carefully made so that the tree can be wrapped back up to heal for future harvests. Once the liquid latex material is collected, ammonia is added to the material to prevent it from hardening prematurely. It is then put through a process of coagulation which thickens the material into a clump. Finally, the material must be dried and solidified for use. To produce a solid rubber material, the liquid raw material is typically vulcanized—a process in which the material is heated with sulfur. This process is why some elastomer sheets are known as vulcanized rubber sheets, and the result is rubber—solid and strong.

Both natural and synthetic types of rubber are resilient and elastic materials differentiated by their chemical makeup. The raw materials that compose these types of rubber are the determining factors of their physical and chemical properties. Natural elastomers retain a high tensile strength, a low compression set, and are highly abrasion-resistant; however, they will not function well when exposed to damaging environmental factors such as UV-rays, ozone, oxygen, and moisture. In contrast, a synthetic rubber sheet holds up well against these factors—while also being stronger and more chemical- and temperature-resistant. The many different types of rubber each have its own set of unique properties. This general fact about rubber as a material means that rubber is highly versatile—able to be augmented to fit a wide range of applications, depending on their needs.