Silicone vs. Siloxane

What's the Difference?

Silicone and siloxane are both types of polymers that contain silicon atoms. However, there are some key differences between the two. Silicone is a synthetic material that is derived from silicon, oxygen, carbon, and hydrogen. It is known for its versatility and is commonly used in various industries, including healthcare, electronics, and construction. On the other hand, siloxane refers to a class of compounds that contain silicon-oxygen bonds. Siloxanes are often used as lubricants, solvents, and in the production of silicone polymers. While silicone is a specific type of siloxane, not all siloxanes are silicone. Overall, both silicone and siloxane have unique properties and applications, but silicone is more widely recognized and utilized in various industries.


Chemical FormulaSi-O-SiSi-O-Si
StructurePolymers with alternating silicon and oxygen atomsPolymers with alternating silicon and oxygen atoms
ApplicationsSealants, adhesives, lubricants, medical implants, cosmeticsSealants, adhesives, lubricants, medical implants, cosmetics
Physical StateCan be liquid, gel, or solidCan be liquid, gel, or solid
Thermal StabilityHighHigh
Chemical InertnessHighHigh
Electrical InsulationExcellentExcellent
Water ResistanceExcellentExcellent
Chemical ResistanceResistant to many chemicalsResistant to many chemicals

Further Detail


Silicone and siloxane are two commonly used materials in various industries, including construction, automotive, electronics, and healthcare. While they share some similarities, they also have distinct attributes that make them suitable for different applications. In this article, we will explore the characteristics of silicone and siloxane, highlighting their strengths and weaknesses.

Chemical Composition

Silicone is a synthetic polymer made up of repeating units of siloxane, which is a chain of alternating silicon and oxygen atoms. Siloxane, on the other hand, refers to the basic building block of silicone. It consists of a silicon atom bonded to two oxygen atoms and two organic groups, typically methyl or phenyl. This unique chemical structure gives silicone and siloxane their exceptional properties.

Thermal Stability

One of the key advantages of silicone is its excellent thermal stability. Silicone can withstand extreme temperatures, ranging from as low as -100°C to as high as 300°C, without losing its physical properties. This makes it ideal for applications that require resistance to heat, such as oven mitts, gaskets, and automotive engine components. Siloxane, being the fundamental component of silicone, also exhibits good thermal stability, although it may have a slightly lower temperature range compared to silicone.

Flexibility and Elasticity

Both silicone and siloxane possess remarkable flexibility and elasticity. Silicone products can be easily molded into various shapes and sizes, allowing for intricate designs and customization. Its inherent elasticity enables it to recover its original shape after being stretched or compressed, making it suitable for applications that require durability and resilience. Siloxane, as the building block of silicone, shares these properties and contributes to the overall flexibility and elasticity of silicone-based materials.

Chemical Resistance

Another notable attribute of silicone and siloxane is their exceptional chemical resistance. They are highly resistant to water, oils, solvents, and many chemicals, making them suitable for applications in harsh environments. Silicone-based sealants, for example, are widely used in construction and automotive industries due to their ability to create a durable and watertight seal. Siloxane, being the primary component of silicone, imparts this chemical resistance to the material.

Electrical Insulation

Both silicone and siloxane exhibit excellent electrical insulation properties. They have high dielectric strength, meaning they can withstand high voltages without conducting electricity. This makes them ideal for electrical and electronic applications, such as insulating wires, cables, and connectors. Silicone-based coatings are also used to protect electronic components from moisture and environmental contaminants. Siloxane, as the fundamental unit of silicone, contributes to its electrical insulation capabilities.


One area where silicone shines is its biocompatibility. Silicone is widely used in medical and healthcare applications, including implants, prosthetics, and medical tubing, due to its non-toxic and hypoallergenic nature. It is well-tolerated by the human body and does not elicit adverse reactions. Siloxane, as the building block of silicone, plays a crucial role in ensuring the biocompatibility of silicone-based medical devices.

Cost and Availability

When it comes to cost and availability, silicone and siloxane differ to some extent. Silicone, being a processed and refined material, tends to be more expensive compared to siloxane. However, silicone is widely available in various forms, including liquid, rubber, and gel, making it accessible for different applications. Siloxane, on the other hand, is often used as a raw material in the production of silicone and may not be as readily available in its pure form.


In conclusion, silicone and siloxane are closely related materials with distinct attributes. Silicone, derived from siloxane, offers exceptional thermal stability, flexibility, chemical resistance, electrical insulation, and biocompatibility. Siloxane, as the building block of silicone, contributes to these properties. While silicone may be more expensive, it is widely available in various forms. Understanding the unique characteristics of silicone and siloxane is crucial in selecting the right material for specific applications in different industries.

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