Elastomers

A polymer is a material that is made up of a large number of repeating components that make up macromolecules. Both artificial and natural polymers play crucial and pervasive roles in everyday life due to their diverse features. Polymers range from ordinary synthetic plastics such as polystyrene to biopolymers such as DNA and proteins, which are required for biological structure and function.

Natural and synthetic polymers are created by polymerizing a large number of small molecules known as monomers. Their large molecular mass, in comparison to small molecule compounds, results in remarkable physical properties such as toughness, high elasticity, viscoelasticity, and a proclivity to form amorphous and semi-crystalline formations rather than crystals.

Polymers

Polymers are high-molecular-mass materials that contain a large number of repetitive structural units that can be produced from simple molecules. They implant macro-sized molecules with a massive molecular mass on the order of 10–10u. Macromolecules is another name for them. The repeating structural units are formed from an infinite number of simple reactive molecules and are held together by covalent bonds.

Classification of polymers based on molecular forces

Polymers are categorised into 4 groups based on intermolecular forces:

1. Elastomers: Elastomers are polymers that have the smallest intermolecular forces of attraction between the polymer chains and have an elastic property, similar to that of rubber. Polymers can be easily stressed by introducing minor pressures and restore their dominant shape when the stress is diverted because of the oncoming weak forces. Natural rubber is the most common type of elastomer. These polymers are made up of molecular chains that are randomly coiled. Buna-S, Buna-N, Neoprene, and other materials with weak intermolecular forces are examples of elastomers.
2. Fibres: Polymers with high intermolecular interactions between the chains are known as fibres. Hydrogen bonds or dipole-dipole interactions are the forces at work. These polymers may be woven into fabric because they are long, thin, and thread-like. As a result, they’re employed to create fibre. Nylon-66, terylene, silk, and other similar materials are common examples. These are thread-forming solids with a high modulus and tensile strength. Polyamides (nylon-6,6), polyesters (terylene), and other polymers contain strong intermolecular forces such as H-bonding.
3. Thermoplastic polymers: Thermoplastic polymers are long-chain molecules with a linear or scarcely radiating structure capable of constantly softening on heating and hardening on cooling. Intermolecular forces of attraction are held in these intermediates between elastomers and fibres. Polyethene, polystyrene, polyvinyl, and other similar materials are examples of thermoplastic polymers.
4. Thermosetting polymers: Thermosetting polymers are those that can be continuously softened on heating and hardened on cooling with just minor changes in their characteristics. The intermolecular forces in these polymers are somewhere between those of elastomers and filaments. Between chains, there is no cross-linking. Due to the lack of cross-links, softening occurs when polymer chains move around freely. Polythene, polystyrene, polyvinyl chloride, Teflon, and other thermoplastics are examples.

Properties of elastomers

• Temperature: The temperature at which elastomers work varies based on factors such as media compatibility, seal design, and dynamic and static operation.
• Low-temperature flexibility: Low-temperature retraction can be used to investigate the rate of recovery of elastomeric materials.
• Hardness: The hardness of a substance is determined by measuring its resistance to a deforming force over a set period of time. It varies depending on the substance. Soft compounds deform readily and have a lot of friction, whereas tougher compounds have a lot of resistance and little friction.
• Ageing: Understanding the behaviour of a substance when exposed to heat is aided by this feature. Hardening, cracking, and splitting will occur if the elastomers are pushed beyond their ageing resistance.
• Colour: Colour is mostly used to distinguish between compound grades based on their intended application.
• Elongation at break: When a material is under tensile stress, this property is utilised to determine the moment of rupture.

Applications of elastomers

Because of their elasticity, flexibility, insolubility, and a variety of other characteristics, they play an important and pervasive role in everyday life. The following are some of their applications:

1. Automobiles: Some elastomers, such as thermoset, do not melt easily, making them useful in the construction of seals, tyres, and other components throughout the automobile design. Particularly those components that will be subjected to heat during operation. Polybutadiene-based materials have exceptional wear resistance, making them ideal for tyre construction.
2. Consumer products include a wide range of items ranging from shoe soles to infant pacifiers and a variety of other items.
3. Constructions: Materials such as adhesives and sealants encased in elastomers, which are an unavoidable element of any building. Especially useful for filling in the blanks.
4. Products for industry: Elastomers are widely utilised in the manufacture of industrial tools, appliances, belts, moulds, and lubricants, among other things.
5. Wire and cable: The materials used to construct wires should be heat resistant, reshapable (elongated), and offer insulation. Neoprene and other elastomers are ideal for this.
6. Medical items: The medical profession requires a diverse range of products such as prosthesis, lubricants, and moulds that are chemically and thermally resistant. Silicon, an elastomer, has been widely employed to manufacture them and a variety of other products.

Conclusion

Elastomers, commonly known as viscoelasticity polymers, are viscosity and elasticity polymers. Elastomers are made up of molecules with weak intermolecular interactions that bind them together. They have a high yield strength or failure strain and a low Young’s modulus. After being stretched to extremes, they have the remarkable ability to restore to their original shape and size.