Ideally, some of the most common types of elastomers in today’s industry is silicone and natural rubber. The two are polymeric materials that display viscoelastic behavior (commonly known as elasticity).
From the atomic structure, you can distinguish between rubber and silicone material. In this regard, let’s explore the difference between silicone and rubber.
Definition
Rubber is a strong elastic polymeric material made from the latex of rubber trees or synthetically in a lab. The chemical name of rubber is polyisoprene.
On other hand, silicone is a synthetic material that constitutes any inert, artificial compound comprising of replicating units of siloxane. The chemical name of silicone is polysiloxane.
1. Backbone Structure
Most types of rubber have a backbone containing carbon-carbon bonds.
However, the backbone structure of silicone includes an alternating oxygen atoms and silicon atoms sequence. Often, you will have the two atoms bonded with hydrogen and/or carbon.
2. Operating Temperature
Although there is no significant implications when using rubber and silicon at low temperatures (-50°C), the main challenge comes in the high temperature limit. That is, at 80°C, natural rubber will start disintegrating. Usually this is not the case for silicone.
Furthermore, at 120°C, natural rubber will start melting while silicone remain in good working condition. Simply put – silicone is temperature resistant. Besides, it can be modified for superior performance.
Silicone also has considerably greater flame resistance in comparison to rubber. Therefore, it is the better option for high temperature uses.
3. Resistance to Hydrocarbon Lubricants and Fuels
Hydrocarbons and fuels have significant impact on both silicone and natural. Nonetheless, silicone displays a broader chemical resistance in comparison to rubber. This makes it a better option in chemical sealing applications.
Still, using either rubber or silicone in any specific application. However, silicone has better chemical resistance hence, its suitability in most pipe and tank lining.
4. Tear and Tensile Strength
Rubber has superior resistance to abrasion and tensile strength. A reason you will find rubber and not silicone in applications requiring extreme wear. A good example is the conveyor system.
5. Ultra-violet Light and Weathering Resistance
Silicone exhibits greater resistance to UV light and weathering. For this reason, you can use it in outdoor applications like window and door seals.
Rubber cannot resist weathering hence silicone is better alternative.
6. Durability
The lifespan of silicone is about 4 times longer than that of rubber. Although its price is approximately double the price of natural rubber. Using silicone, therefore, might help you save on cost in the long-term.
7. Stabilizing Additives
You need special additives for stabilizing rubber. However, quality silicone production does not need addition of any stabilizing agent.
Other Differences between Silicone and Rubber
| Properties | Silicone | Natural Rubber |
| Chemical Attack | Less resistant to most chemicals | Exceptional resistance to most chemicals |
| UV and ozone | Less resistance | Better resistance than natural rubber |
| Thermal insulation | Not very suitable | Exception thermal insulation |
| Source of material | It comes from natural resource though synthetic options are available | Mainly synthetic |
| Weathering resistance | Poor properties | Superior properties |
8. Applications
Silicone material come in different grades. The FDA approved options are best for medical and food industries. Its durability, high temperature and abrasion resistance makes it the better option in comparison to rubber.
A versatile more hygienic structure, less contamination, and long term cost savings all add to the benefits of using silicone.
Quick FAQs
Is Rubber and Silicone the Same?
The two are elastomers. However, their production and chemical composition vary. Hence, the variations in the physical and chemical properties.
Is Rubber Cheaper than Rubber?
Silicone is a specialty elastomers with exceptional properties hence the high cost. The high silicone cost is also attributed to the complex manufacturing process.
Conclusion
As you can see, silicone is a perfect choice for more specialized applications than rubber. However, before choosing any of these materials, you should know their physical and chemical properties.
If you have any questions on silicon or rubber materials, contact us now.