What is rubber deformation?

What is rubber deformation?

Definition. Elastic deformation is a change of the shape of the body as a reaction to applied stress. This deformation is only temporary and once the stress is released, the undeformed shape of the body is restored, as shown in the figure below.

What is a material like rubber?

Elastomers or rubber-like materials have been used as an engineering material for nearly 150 years. The term elastomer, which is derived from elastic polymer, is a polymer which has the property of viscoelasticity, with low Young’s modulus and high yield strain.

Can rubber be deformed?

Rubber-like materials used in the engineering practice often undergo large deformations. Due to superior elastic properties, rubber remains elastic up to very large strain and therefore can be considered as a classical example of finite strain elasticity.

What is rubber elasticity theory?

The statistical theory of rubber elasticity predicts that the stress in a strained elastomer is proportional to absolute temperature. According to the statistical theory of rubber elasticity, a 31% reduction in absolute temperature will result in a 31% reduction in sealing stress.

What is plastic and elastic deformation?

Elastic deformation is the deformation that disappears upon removal of the external forces causing the alteration and the stress associated with it. Plastic deformation is a permanent deformation or change in shape of a solid body without fracture under the action of a sustained force.

What are elastomers examples?

Elastomers. Examples of elastomers include natural rubbers, styrene-butadiene block copolymers, polyisoprene, polybutadiene, ethylene propylene rubber, ethylene propylene diene rubber, silicone elastomers, fluoroelastomers, polyurethane elastomers, and nitrile rubbers.

Is there an alternative to rubber?

Some plants that have been considered as alternative rubber sources are guayule, Russian dandelion, rubber rabbit brush, goldenrod, sunflower, fig tree, and lettuce. Two of these plants seem to be the best alternatives to Hevea brasiliensis: guayule and Russian dandelion.

Is silicone same as rubber?

Silicone is a form of synthetic rubber. Therefore, it also is a type of elastomer as rubber. The key difference between rubber and silicone is that the backbones of most of the rubber forms contain carbon-carbon bonds while the backbone of silicone contains silicon and oxygen.

Does rubber have plastic deformation?

Hard thermosetting plastics, rubber, crystals, and ceramics have minimal plastic deformation ranges. An example of a material with a large plastic deformation range is wet chewing gum, which can be stretched to dozens of times its original length. Plastic deformation ends with the fracture of the material.

What makes rubber stretchy?

The reason rubber bands stretch is because when you pull on the rubber band, the polymers (which are normally coiled up more or less at random) get stretched lengthwise and the rubber band is lengthened. This will cause the polymers to stretch and the rubber band to lengthen.

What is the chemical composition of natural rubber?

Natural rubber consists almost entirely of the cis-1,4 structure and hence is, chemically, cis-1,4 polyisoprene. When the chain units in a polymer consists of the same isomer it is said to be stereoregular.

How is stress related to the deformation of rubber?

In case of undeformed rubber the stretch ratio is 1 and the stress will be 10 x (1 – 1) = 0 MPa. A stress will cause a deformation in a body. In case of small deformations the stress is proportional to the strain (Hooke’s law). Hooke’s law says that the stress is equal to the elasticity modulus times the strain.

What’s the difference between harder rubber and softer rubber?

Softer rubber has a higher coefficient of friction and harder rubber has a lower coefficient of friction. Coefficient of friction plays a factor when the rubber seal is sealing a part that moves.

How are elastomers related to the elasticity of rubber?

Rubber Elasticity. High molecular weight polymers that exhibit rubber-like behavior are known as elastomers. Above the glass transition temperature, the rubber-like polymers are in a liquid-like state and the mer or repeat units change their position readily and continuously due to Brownian motion.

What is the definition of deformation in Materials Science?

In materials science, deformation refers to modifications of the shape or size of an object due to applied forces or a change in temperature. Deformation is usually caused by forces such as: Tensile (pulling)