Elastomers: Definition, Properties, Applications.

Each day, we fall back on a vast array of materials and items to get by, most of which we hardly notice. The elastomers are one example; they are now used in various industries and applications. Elastomers play a crucial role in many aspects of modern life, from the tyres on our automobiles and the plastic containers to the seals and components we use in manufacturing equipment. Despite this, many individuals aren’t clear about elastomers, their significance, or how widely they’re employed in many sectors.

What are Elastomers?

The most common nickname for elastomers is “rubber,” yet this only gives people a general sense of their characteristics and uses. In chemistry, elastomers can be defined as long-chain polymers of carbon, silicon, hydrogen, and oxygen, having intermolecular cross-links in their chemical structures. Materials with these chemical characteristics are viscous and stretchy.

It can be easily understood as a ball of tangled strings. The knots connecting the strings stand in for the cross-links in a polymer chain, and each string is one of those chains. The cross-links will prevent the strings from easily stretching apart when pulled under compression in the direction where the force is applied. The cross links ensure that the elastomer returns to its initial shape when the load is released. Without the extensive strings or cross-links, applying force to the material would cause it to distort permanently. 

Thus, the length, strength, and distribution of polymeric cross-links in an elastomeric material affect the substance’s precise properties.

Classification of Elastomers

Based on their particular chemical structures, elastomers can be classified into the following categories:

Thermoset Elastomers:

These elastomeric substances do not break down (melt) when heated. These are the most commonly used elastomers. Thermoset elastomers typically need vulcanisation, a chemical hardening procedure that creates cross-links in a polymer chain to strengthen the rigidity and endurance of rubber goods.

Thermoplastic Elastomers:

The cross-links in thermoplastic elastomers are substantially weaker than those in normal elastomers. When heated, these elastomers allow the material to break down (melt) and reform without compromising its elastomeric qualities. These elastomers stretch farther than thermosets and are typically simpler to use in manufacturing. They are also easier to recycle.

Examples of elastomers include silicone elastomer, natural rubber, polyurethane, neoprene, and polybutadiene.

Properties of Elastomers

Despite appearances, rubber has a diverse range of physical properties depending on the kind and chemical composition of the material. The two most important properties of elastomers, viscosity and elasticity of elastomers, are further discussed below: 

Viscosity: Viscosity can be defined as the substance’s capacity to flow. The degree of viscosity reflects how swiftly or slowly a liquid moves under force. For instance, when pouring oil over water from a glass, the oil flow is substantially slower compared to water, indicating it is more viscous. Elastomers typically have high viscosities, which causes them to flow when forced.

Elasticity: An object’s elastic properties refer to its capacity to regain its initial shape after being externally stretched or compressed. A rubber band is its best example; when stretched, it returns to its original shape. High levels of elasticity are a characteristic of elastomeric polymers, which makes them more resilient to breaking and cracking. Elastomers can transiently extend up to 700 per cent depending on the particular material.

Elastomers also have several other qualities in addition to these two.

Temperature: Each type of elastomer has a defined operating temperature. However, this will depend on several variables, including seal design, media tolerance, dynamic or static operation, and many more. Numerous factors influence the operating temperature of elastomers. Elastomers stretched to their absolute limit may experience a rapid loss of elasticity and excessive compression set.

Low-temperature flexibility: The rate of recovery of elastomers can be evaluated by subjecting the material to low-temperature retraction.

Hardness: The process of assessing hardness involves determining how long a substance will withstand being deformed by force. It varies from substance to substance. The tougher compounds have strong resistance and low friction, whereas the soft compounds easily bend and have high friction.

Ageing: Heat ageing tests are frequently used to track changes in an elastomer’s properties. Typically, measurements and comparisons to original parameters are made for hardness, tensile strength, and elongation. This characteristic makes it easier to comprehend how a material will perform in a hot environment. The elastomers will experience hardness, breaking, and splitting if their ageing resistance is exceeded.

Colour: Colour is mostly used to distinguish compound classes according to their intended application. Carbon black fillers are frequently used in the formulation of rubbers. As a result, the vast majority of elastomers are dark in colour. Carbon black fillers are added to rubbers to increase their strength and temperature resistance.

Elongation at break: When a material is subjected to tensile stress, the elongation at break property is used to determine when the material will break.

Types of Elastomers

Elastomers are employed in many industries for many applications because of their special characteristics. Some of the commonly used elastomer types and their applications in various sectors are listed below:

Natural Rubber:

Natural rubber is composed of the isoprene organic compound from the rubber plant. It is extremely elastic and robust but is prone to ageing and inflating in the presence of oil, making it less suitable for seal manufacturing. Natural rubber is most widely used to make anti-vibration materials, latex goods, wearable products including shoes and rubberised fabrics, and automobile parts.

Polyurethane Elastomer:

Polyurethane elastomer is incredibly adaptable in manufacturing and is capable of producing durable, dependable products. Polyurethane elastomer is typically heavily utilised in the textile sector to create elastic apparel like spandex. Thermoplastic polyurethane elastomer is also utilised in producing technical components, including shoes, pillows, cables, seals, and fittings.

Polybutadiene Elastomer:

It is a significant elastomer, particularly in creating vehicle tyres, when combined with other rubbers, such as natural rubber or styrene.

Neoprene:

Neoprene is most well-known for its application in wetsuits. Additionally, this synthetic rubber is extremely resistant to deterioration, making it ideal for use in hoses, coatings, and gaskets that resist corrosion.

Silicone Elastomer:

Unlike other elastomers made of hydrogen and carbon atoms, silicone elastomers are made of silicon and oxygen atoms. Silicone elastomer is a magnificent all-purpose elastomer frequently used in aerospace, automotive, food, medical, manufacturing, and consumer product applications. It is more resistant to harsh temperatures, ageing, and environmental variables.

Dielectric Elastomers (DEs):

Dielectric Elastomers (DEs) are cognitive systems of material that generate significant strain. The category of electroactive polymers includes these dielectric elastomers (EAP). Here electric energy is converted into mechanical motion. They are light in weight and possess high flexural density. 

Fluoroelastomers:

Fluoroelastomers, also referred to as fluorocarbon compounds, are used in many highly demanding applications. The primary characteristics that distinguish fluoroelastomers from other materials include long-term dependability and minimal environmental impact. These elastomers were created with the sole purpose of being extremely resistant to high temperatures (204°C continuously, 300°C intermittently) and harsh chemical changes. Fluoroelastomers possess excellent compression, UV and ozone resistance, and a low gas absorption rate.

Applications of Elastomers

Elastomers play a significant and pervasive role in daily life. It features high flexibility, elasticity, insolubility, and numerous other unique qualities. Here is a common list of some of their applications:

Automobiles:

Thermosets are an example of an elastomer that doesn’t melt readily, making them useful for creating seals, tyres, and other components throughout the automobile design. Specifically, in those parts that will be heated up during the production process. The polymer of the type polybutadiene has exceptional wear resistance; as a result, it is preferred in the construction of tyres.

Consumer goods:

This category includes the broadest range of goods, from infant baby toys to rubber soles and many other unrelated items.

Constructions:

Materials such as sealants and adhesives encased in elastomers are necessary for all construction. Particularly for bridging the cracks.

Industrial Products:

Elastomers are extensively employed in producing industrial equipment, appliances, belts, moulds, lubricants, etc.

Wire and Cable:

The materials used to construct wires should be heat resistant, flexible (able to be extended), and insulating. Neoprene and other elastomers are ideal for this.

Medical Equipment:

The medical industry requires a broad range of products, including prosthetics, lubrication, and moulds with exceptional chemical and thermal resistance. Silicone elastomers are mostly used to construct these types of equipment.

Conclusion

Several manufacturers may offer elastomeric materials, but you must choose the appropriate one to deliver consistent quality each time. Choosing a low-quality source can result in a significant increase in costs in productivity, and working with multiple vendors may cost you money and time to determine which good or service is most dependable. Lion Elastomers are available to assist.

When you choose Lion Elastomers, you choose a business with years of expertise. Along with providing customised rubber products to meet your specific needs, they also supply drilling machine parts, packer cups, oil well casings, and other essential items for your business. Whatever your business needs, Lion Elastomers can deliver it.

Frequently Asked Questions

1. What is the purpose of fluoroelastomers?

Fluoroelastomers are primarily employed in industrial seals and barrier layers. These are subjected to harsh environments that other elastomers cannot withstand. Fluoroelastomer parts can tolerate sustained temperatures of more than 300°C (572°F) and have prolonged serviceability at temperatures above 150°C (302°F).

2. What are elastomers?

An elastomer is any rubber-like substance made up of long chain-like atoms, often known as polymers, that can regain its previous shape after being greatly stretched.

3. What are the primary uses of an elastomer?

Elastomers are mainly used in the automobile industry for making rubber tyres and tubes, bicycles, motorcycles, recreational vehicles, lawnmowers, and other tools for yard work, hoses, belts, matting, gloves, rubber bands, toy balloons, pencil erasers, and adhesives.