January 21, 2019

Silicone and rubber presents a group elastomeric materials that exhibit viscoelastic characteristics owing to their amorphous structures. Rubber can be differentiated from silicone from their atomic structures in that Silicone comprises of repeated siloxane units while rubber contains alternating chains of carbon and hydrogen. There different pros and cons with each material, it all depends on your application.

Silicone exhibit excellent resistance to UV light and weathering hence used in most outdoor applications including window and door seals. On the other hand, rubber weathers fast and are not suitable for outdoor applications. Rubber shows poor resistance to UV and ozone weathering. They will dry-up and harden with prolong exposure to the external elements, rubber will eventually crack and fail.

The temperature resistance of silicone rubber is also much better than rubber. Silicone rubber maintains its physical and chemical properties over a large temperature range.

Natural Rubber : -50oC to 85oC
Neoprene : -45oC to 135oC
EPDM : -55oC to 150oC
Silicone Rubber : -40oC to 230oC

The product durability of silicone-based products is higher than those made of rubber. This factor is considered a financial issue by various industries that uses this materials. As such, silicone is said to last about four times more than rubber even though its price ranges approximately two times higher than rubber. In the long run, use of silicone in applications is more economical as compared to rubber.

During manufacturing, toxic additives are used to increase the stability of the material. Despite the efforts to limit the application of carcinogens in rubber production, the option is still inevitable to date. However, the process of producing silicone products of high quality doesn’t call for addition of stabilizing additives which are considered questionable. Due to its chemical stability and also a generally inert product, silicone rubber is often used in the food and beverage industry.

silicone milk bottle nipple
Photo : Silicone Milk Bottle Nipple

In terms of mechanical properties, silicon has lower abrasion resistance, tear strength, and tensile strength compared to natural rubber. For this reason, rubber finds applications in areas subjected to high wear like the conveyor belts and tires. On the contrary, silicone may fail in such applications due to their lower wear and abrasion resistance.

Both rubber and silicone have poor resistance to lubricants and hydrocarbon fuels. Nevertheless, the chemical resistance of silicone is relatively higher than that of rubber. However, we would recommend using our braided fuel hoses for these types of applications. We have other types of rubber other than silicone rubber!

braided fuel hose
Photo : We also carry Braided Fuel Hoses

The compression set performance of both silicone and rubber is good and are considered great material choices for seals or other static applications.

In summary, both materials stand out under different circumstances. Therefore it is imperative to understand the needs and requirements of your process to find an optimal material. Not sure which works better? Contact us and let us help you out. We have other materials that may suit your needs.