Is Rubber An Insulator? 5 Facts You Should Know

Rubber is elastic and can return to its original shape after being deformed through stretching and bending. Let us focus on the possibility of rubber behaving like an insulator.

Rubber is an insulator as it is a non metal. Non metals do not have free electrons that carry electricity in them. They only have those electrons that are strongly bound to the orbits of an atom with the nuclear force of attraction. This strong force does not allow e⁻s to move to conduct current.

Movement of immobile electrons or charge carriers in a definite direction in a material usually conducts electricity. But in rubber this movement is absent making it an insulator. Let us go through how rubber is an insulator,why it does not conduct electricity and facts related to whether rubber is an insulator or not.

How rubber is an insulator?

Insulators are those materials which have very low values of electrical conductivity. Let us go through the process of rubber acting as an insulator.

Rubber is an insulating isoprene by having strong sigma bonds equipped with non overlapping weak pi bonds. These two types of bonds make all the lowerly energized electrons in the valence band to not move to the high energy conduction band in rubber and resist the flow of current.

Rubber has conjugated molecules. These molecules contain pi bonds in 2,6,10 or 1,5,9 positions. This transformation of overlapping pi bonds into sigma and non overlapping pi bonds produces a huge energy gap between the valence band and conduction band of rubber making rubber an insulator.

Why does rubber not conduct electricity?

A material can be picked as a conductor or an insulator in terms of its electrical conductivity. Let us have a look at the reason why rubber is not able to conduct electricity.

Rubber does not conduct electricity because it has the property of restricting the flow of delocalized electrons in it. In the influence of applied voltage the e⁻s that are placed in the valence shell of rubber atoms do not get enough energy to move to the conduction band and this, in turn, behaves like an insulator.

Insulators are those materials in which the energy gap between the valence band and conduction band is high. Besides that rubber has a very low value of electrical conductivity making it a good insulator.

Uses of rubber as an insulator

Different types of rubbers have several uses due to their insulating properties that have grown due to the vulcanisation process. The uses of rubber are:

  • Insulating footwears and insulating blankets used to be made using crepe rubbers.
  • Uncured rubbers do have extended uses in the insulating materials.
  • Vulcanized rubber is used to cover many appliances as it has the capacity to absorb electric vibration.
  • In the early time rubber had extensive use as sheathing substance and cable insulator.
  • Rubber cables are used hugely over the other insulating cables because they are more flexible to use in a long temperature range.
  • Electrical appliances,power tools,pumps and electric generators do have extensive uses of rubber cables as trailing leads due to their high values of abrasion resistance and weathering resistance.
  • Chemicals especially oils are combined with rubber to make compounds that have excellent resistances.
  • Rubber insulation sheets are made of rubber,an organic latex found from rubber trees due to its speciality of not being damaged in a high voltage. Besides it is also preferable due to its excellent elasticity property which stops it from breaking easily.
  • Rubber insulating sheets are used in power stations and industrial purposes. The floors of power stations can be insulated using these sheets.
  • Rubbers have uses in the mining industry and transportation equipment too.
  • Rubbers are used in making handles of saucepans due to its insulation capacity to protect the heat flow to the cook’s hand and prevent from burning.

Is rubber an insulator of heat?

Rubber is a natural product with elasticity and insulating properties. Let us focus on whether rubber is an insulator of heat or not.

Rubber is an insulator of heat. Rubber does not allow heat to transfer from one place to another which is the reason for it to be an insulator. In the heat conduction process the molecules of high temperature seek to travel to other low temperature molecules to pass heat and this does not happen in rubber.

Besides the reason stated above, rubber has a very low value of thermal conductivity in the range of 0.09 W/m.K to 2.5 W/ m.K at room temperature. This also helps rubber in retaining its insulating properties of heat.


Rubber is an insulator with so many uses in different industries. In this article all the concepts related to the reason for rubber being an insulator of both heat and electricity and the process of how rubber acts as an insulating material and its uses are clarified in simple words and in a brief manner.

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