Silicone and latex are both elastomer materials.
This means they are able to regain their original dimension when you stretch them.
But there is considerable difference in chemical composition, processing methods, and physical properties of silicone vs latex.
That said, let’s explore the key differences between latex and silicone.
Definition
Silicone rubber is a type of synthetic rubber produced by polymerizing siloxanes with oxygen while using other elements as catalysts.
The resulting polymers are known as polysiloxanes.
You can modify polysiloxanes further with functional groups.
The properties of silicone rubbers depend on their molecular structure.
Silicone Rubber
In contrast, latex is a natural material made from gum/sap extracted from rubber trees.
It is the most widely used natural polymer.
1. Chemical Composition
Silicone is a synthetic polymer having a silicon-oxygen backbone.
The simplest silicone molecule comprises of two linked silicon atoms attached to two oxygen atoms.
These molecules are known as siloxane polymers or chains.
They come in different lengths depending on how many silicon and oxygen atoms are linked together.
Latex has a carbon-carbon backbone structure. The primary chemical constituents of latex are isoprene polymers.
Hydrogen bonds connect these polymers to form polyisoprene that makes up the latex material.
2. Cold And Heat Resistance
Silicone withstands low and high temperatures way better than latex.
You can use silicone product indefinitely at 150 degrees Celsius with nearly no alteration in its characteristics.
Some silicone rubber can sustain heat as high as 350 degrees Celsius for short periods.
Therefore, silicone materials are ideal for rubber components utilized in high temperature applications.
Moreover, silicone also exhibits excellent cold temperatures resistance.
The embrittlement points of standard latex ranges between -20 to -30 degrees Celsius.
This compares to -60 to -70 degrees Celsius for silicone rubber.
Latex Sheet
Silicone material stays elastic even at temperatures where latex turns brittle.
Some withstand temperatures as low as -100 degrees Celsius or lower.
3. Tensile Strength
Compared to latex, silicone exhibits a lesser tensile strength.
The approximate tensile strength of silicone is 5 MPa while that of latex is 25 MPa.
4. Resistance to Solvents, Oils, and other Chemicals
Silicone rubber material has excellent oil resistance at high temperatures.
Some latex types have fairly higher resistance at below – 100 degrees Celsius temperatures. Nevertheless, silicone is superior at higher temperatures.
Compared to latex, silicone also has better resistance to solvents and additional chemicals.
Dilute acids/bases, or organic compounds have negligible effects on them.
The volume increases because silicone swelling ranges between 10 – 15 percent.
Silicone materials do swell inside non-polar organic compounds such as gasoline, toluene, and benzene.
However, unlike most latex materials, it does not dissolve or decompose. The material will regain its original state when you remove the solvent.
Nonetheless, strong bases and acids adversely affect silicone rubber.
Therefore, you should not use it in applications where the material will interact with such chemicals.
5. Thermal Conductivity
Silicone has a thermal conductivity of around 0.2 W/mΩ·K. This value is higher compared to that of natural latex.
Certain silicone materials include a high percentage of unique inorganic fillers that enhance thermal conductivity (approximately 1.3 W/mΩ·K).
You can use these materials to manufacture heating rollers and thermal interface sheets.
6. Electrical Insulation
Silicone has a higher insulation resistance than latex.
Its insulating characteristics remain stable across a broad frequency and temperature range.
There is nearly no reduction in performance even if you submerge it in water.
Silicone specifically has good resistance to arcing and corona discharge at high voltages.
Therefore, it is a perfect insulating material for high-voltage applications.
7. Weatherability
Silicone rubber has outstanding weatherability. Ozone due to corona discharge has almost zero impact on it.
But the ozone rapidly disintegrates most latex materials.
Furthermore, you can expose silicone material to rain, UV light, and wind for a prolonged duration with practically no modification in it physical features.
8. Radiation Resistance
Latex has better resistance to radiation than silicone rubber.
But, silicone materials with adjoined phenyl groups exhibit excellent radiation resistance.
Fresh Natural Latex Rubber
They find application in production of connectors and cables used within nuclear power plants.
9. Coloring and Transparency Features
Most latex products are black because of their carbon constituents.
In contrast, you can produce highly transparent silicone products.
This is due to the fact that the fine silica content does not upset the natural silicone transparency.
The high transparency of silicone makes coloring it with pigments easy.
Therefore, you can create colorful molded products using rubber material.
10. Gas Permeability
Compared to natural latex, silicone rubber displays better vapor and gas permeability.
One application of silicone under investigation is using it as a water and gas separation membrane within oxygen enrichment systems.
11. Flex Fatigue Resistance
Generally speaking, latex has better strength against dynamic stress than silicone material.
Silicon Baking Molds
12. Longevity
Latex is a dying substance that begins to change immediately you produce it.
Pressure, UV light exposure, stress and temperature changes will increase the rate of damage. These elements can affect texture, color, density and hardness of latex.
Nevertheless, extreme temperatures, UV light, and other elements exposure does not affect silicone. Therefore, the shelf life of silicone is longer in comparison to latex.
Conclusion
With this detailed comparison, it is upon you to decide which material to choose for your applications.
Today, silicon is a popular material for many industrial and home applications.
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