Is Rubber a Conductor? (+ 3 Things to Know)

No, rubber is not a conductor. Rubber is an insulator, which means it does not allow the flow of electric current. 1 It has high electrical resistance, preventing the movement of electrons and making it a poor conductor of electricity.

Well, this was just a simple answer. But there are few more things to know about this topic which will make your concept super clear.

So let’s dive right into it.

Key Takeaways: Is Rubber a Conductor?

  • Rubber is an insulator because its molecular structure does not allow for the flow of electrons.
  • Rubber’s insulating properties can be affected by temperature, moisture, contaminants, and aging.
  • Rubber is widely used as an electric insulator in various applications, such as electrical wiring, electrical equipment, power transmission, electronic devices, surge protection, and electrical safety gear.

Why is rubber an insulator?

Rubber is an insulator because of its molecular structure and properties. Rubber, also known as an elastomer, consists of long polymer chains made primarily of carbon and hydrogen atoms. 2 These chains are highly flexible and have covalent bonds that do not readily allow the movement of electrons.

In an insulator, electrons are tightly bound to their respective atoms and do not move easily. When an electric field is applied, the electrons in rubber do not have the freedom to move and conduct electricity. The high resistance to electron flow prevents the transfer of electrical charges, making rubber a good insulating material.

Additionally, rubber is also a good insulator due to its high resistivity and low thermal conductivity. It does not readily allow the flow of heat, making it suitable for applications where thermal insulation is required.

Overall, the molecular structure of rubber and its properties, including its ability to resist the flow of electrons and heat, contribute to its insulating characteristics.

Are there any temperature or environmental conditions that can influence the insulating properties of rubber?

Yes, temperature and environmental conditions can affect the insulating properties of rubber. Here are a few factors to consider:

  • Temperature: Rubber’s insulating properties can be influenced by temperature. 3 At higher temperatures, rubber tends to become softer and more pliable, which can decrease its ability to maintain its insulating properties. Conversely, at extremely low temperatures, rubber may become brittle and lose its flexibility, potentially affecting its insulating capabilities.
  • Moisture: Rubber is generally resistant to moisture and can maintain its insulating properties in humid conditions. However, prolonged exposure to moisture or immersion in water can degrade the rubber and compromise its insulating capabilities. Moisture can also affect the surface resistance of rubber, potentially altering its electrical insulation properties. 4
  • Contaminants: Exposure to certain contaminants, such as oils, solvents, or chemicals, can impact the insulating properties of rubber. These substances can degrade the rubber material, reducing its resistance to electrical conductivity.
  • Aging and Degradation: Over time, rubber can undergo aging and degradation, resulting in changes to its molecular structure. This can lead to a decrease in its insulating properties. Factors such as exposure to UV radiation, ozone, or mechanical stress can accelerate the aging process of rubber. 5

Therefore, it is important to consider these factors and choose the appropriate type of rubber or take necessary precautions when using rubber as an insulating material in different temperature and environmental conditions.

Uses of rubber as an insulator

Rubber is widely used as an electric insulator in various applications due to its excellent insulating properties. Here are some common uses of rubber as an electric insulator:

  • Electrical Wiring: Rubber is commonly used in the insulation of electrical wires and cables. It helps to prevent the flow of electricity from the conductive wires to the surroundings or other conductive materials, ensuring safe and reliable electrical connections. 6
  • Electrical Equipment: Rubber is utilized in the insulation of electrical equipment such as transformers, generators, motors, and switches. It helps to insulate the internal components and prevent electrical leakage or short circuits.
  • Power Transmission: Rubber insulators are employed in overhead power transmission lines to support and insulate the conductive cables from the supporting structures. 7 These insulators provide electrical insulation and prevent the transmission of electrical current to the ground.
  • Electronic Devices: Rubber is used in the insulation of various electronic devices, including capacitors, printed circuit boards (PCBs), and connectors. It helps to protect sensitive electronic components from electrical interference and ensures proper functioning.
  • Surge Protection: Rubber insulators are employed in surge protectors and electrical safety equipment to prevent excessive voltage or current from damaging sensitive devices. Rubber’s insulating properties help redirect or absorb electrical surges, safeguarding connected equipment.
  • Electrical Safety Gear: Rubber gloves, mats, and blankets are commonly used by electricians and electrical workers as personal protective equipment (PPE). 8 These rubber insulating materials provide a barrier against electrical shocks and protect individuals from coming into contact with live electrical parts.

In summary, rubber’s insulating properties make it a valuable material for numerous electrical applications, providing safety, reliability, and protection against electrical hazards.

Further reading

Why is Silver a Conductor?
Why is Gold a Conductor?
Why is Brass a Conductor?
Is Carbon a Conductor?
Why is Graphite Conductive? 

About author

Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. He is a founder of Pediabay and is passionate about helping students through his easily digestible explanations.

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  2. Plastics | MATSE 81: Materials In Today’s World. (n.d.). Plastics | MATSE 81: Materials in Today’s World.
  3. Abdel Kader, M., Abdel-wehab, S., Helal, M., & Hassan, H. (2012, April). Evaluation of thermal insulation and mechanical properties of waste rubber/natural rubber composite. HBRC Journal, 8(1), 69–74.
  4. Arshad, Nekahi, A., McMeekin, S. G., & Farzaneh, M. (2017, October 26). Measurement of surface resistance of silicone rubber sheets under polluted and dry band conditions. Electrical Engineering, 100(3), 1729–1738.
  5. Zhu, Y., Ma, B., Liu, X., Song, B., & Zhang, X. (2013, October). Aging performance of silicone rubber exposed to UV and sandstorm. 2013 Annual Report Conference on Electrical Insulation and Dielectric Phenomena.
  7. Shen, W. (2021, November 1). Simulation Research on Electric Field Distribution of Insulator String in ULTRA High Voltage Transmission Line. Journal of Physics: Conference Series, 2108(1), 012024.
  8. 1910.137 – Electrical Protective Equipment. | Occupational Safety and Health Administration. (n.d.). 1910.137 – Electrical Protective Equipment. | Occupational Safety and Health Administration.

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