What Are Silicone and Rubber?

Understanding the core differences between silicone and rubber starts with their origin and molecular makeup. While both are classified as elastomers—materials with elastic properties—they are fundamentally different in structure, performance, and application scope.

Rubber: Natural and Synthetic Origins

Rubber, in its broadest sense, can be either natural or synthetic. Natural rubber is harvested from the latex of rubber trees, while synthetic variants are created through polymerization of petroleum-based monomers. Common synthetic rubbers include:

• NBR (Nitrile Butadiene Rubber) – excellent oil resistance, used in automotive and industrial seals.
• EPDM (Ethylene Propylene Diene Monomer) – superb UV and ozone resistance, ideal for outdoor and roofing applications.
• CR (Neoprene) – good weather and flame resistance, often used in protective gear and adhesives.
• SBR (Styrene-Butadiene Rubber) – a general-purpose rubber often found in tires and footwear.

Despite their differences, these rubbers share certain common traits: good mechanical strength, elasticity, cost-effectiveness, and customization flexibility. However, their performance can vary significantly depending on chemical composition.

Silicone: A Synthetic Elastomer

Unlike carbon-based rubbers, silicone is made from a silicon-oxygen backbone, derived from silica (sand). This fundamental difference gives silicone some unique properties not found in traditional rubbers.

• Extreme temperature resistance: -60°C to +230°C (and even higher for some formulations)
• Outstanding UV, ozone, and weather resistance
• Biocompatibility: safe for medical, food, and baby care applications
• Low toxicity and inertness: does not support microbial growth or react with most chemicals

Silicone (VMQ): Best for Extreme Temperature Flexibility & Food-Grade Applications
Key Features
Excellent heat and cold resistance
Very flexible and elastic
Food-grade and medical-grade availability
Good electrical insulation properties
Temperature Range
–60°C to +200°C
Best Applications
Food & beverage equipment
Medical devices
Oven, heater, and high-temperature appliances
Electronics and automotive interiors
Seals requiring high flexibility
Limitations
Poor tear and abrasion resistance
Not suitable for dynamic sealing
Not ideal for oil and fuel environment

However, silicone tends to have lower tensile strength and tear resistance compared to rubber. It’s also more expensive and not ideal for oil-intensive environments.

In short: Rubber is diverse, strong, and economical. Silicone is specialized, clean, and heat-resistant.

Rubber materials are widely used in various industries due to their unique physical and chemical properties. However, different types of rubber materials have different properties, which can greatly affect their performance in different applications. In this article, we will compare the performance of 10 common rubber materials and discuss their chemical and physical properties.

1.Natural Rubber (NR)

Natural rubber is a widely used elastomer with excellent mechanical properties such as high elasticity, good tensile strength, and tear resistance. It also has good resistance to abrasion and low-temperature flexibility. However, natural rubber has poor resistance to ozone, oxygen, and light, which can lead to cracking and degradation over time.

2.Styrene Butadiene Rubber (SBR)

Styrene Butadiene Rubber is a synthetic rubber made from the copolymerization of styrene and butadiene. It has good abrasion resistance, low-temperature flexibility, and resistance to water and chemicals. However, SBR has poor resistance to sunlight, ozone, and oxygen, which can cause it to degrade over time.

3.Butyl Rubber (IIR)

Butyl rubber is a synthetic rubber with excellent air retention properties. It has good chemical resistance, low gas permeability, and is resistant to water and steam. However, butyl rubber has poor resistance to oil and ozone, which can lead to degradation over time.

4.Nitrile Rubber (NBR)                                                                                                               

Nitrile rubber is a synthetic rubber with good oil and solvent resistance. It also has good mechanical properties such as high tensile strength and good abrasion resistance. However, NBR has poor resistance to sunlight and ozone, which can cause it to degrade over time.

NBR (Nitrile Rubber): Best for Oil & Fuel Resistance
Key Features
• Excellent resistance to oils, fuels, and grease
• Good mechanical strength and abrasion resistance
• Affordable and widely used
• Common hardness: 60–90 Shore A
Temperature Range
–40°C to +120°C
Best Applications
• O-rings and gaskets for hydraulic systems
• Fuel system seals
• Pneumatic seals
• Automotive components
• Compressor and pump seals
Limitations
• Poor weather and ozone resistance
• Not suitable for high temperatures

5.Ethylene Propylene Diene Monomer(EPDM)

Ethylene Propylene Diene Monomer is a synthetic rubber with good resistance to ozone, UV, and weathering. It also has good chemical resistance and low-temperature flexibility. However, EPDM has poor resistance to oils and solvents, which can cause it to degrade over time.

EPDM (Ethylene Propylene Diene Rubber): Best for Weather & Hot Water Resistance
Key Features
Excellent ozone, UV, and weather resistance
Outstanding performance in steam and hot water
Good flexibility at low temperatures
Not affected by outdoor exposure
Temperature Range
–50°C to +150°C
Best Applications
Outdoor seals and gaskets
Drinking water systems
HVAC systems
Brake systems (non-oil environments)
Electrical insulation
Limitations
Not compatible with oils, fuels, and hydrocarbons

6.Chloroprene Rubber (CR)

Chloroprene rubber is a synthetic rubber with good resistance to oils, chemicals, and ozone. It also has good mechanical properties such as high tensile strength and good abrasion resistance. However, CR has poor resistance to hot water and steam, which can cause it to degrade over time.

7.Silicone Rubber (VMQ)

Silicone rubber is a synthetic rubber with excellent resistance to heat, cold, and UV. It also has good electrical insulation properties and is resistant to water and chemicals. However, silicone rubber has poor tear resistance and can be difficult to bond to other materials.

8.Fluorocarbon Rubber (FKM)

Fluorocarbon rubber is a synthetic rubber with excellent chemical resistance and high-temperature stability. It also has good resistance to oil and gas. However, FKM has poor resistance to ketones and esters, which can cause it to degrade over time.

FKM (Viton®/Fluoroelastomer): Best for High Temperature & Harsh Chemicals
Key Features
• Excellent high-temperature stability
• Superior chemical resistance
• Outstanding resistance to fuels, solvents, and aggressive media
• Very low compression set
• Premium performance material
Temperature Range
–20°C to +200°C (up to 250°C for special grades)
Best Applications
• Automotive fuel systems
• Aerospace sealing components
• High-temperature valves and pumps
• Chemical processing equipment
• Oil & gas industries
Limitations
• Higher cost
• Poor performance in very low temperatures

9.Polyurethane Rubber (PU)

Polyurethane rubber is a synthetic rubber with excellent resistance to abrasion, tear, and impact. It also has good mechanical properties such as high tensile strength and elasticity. However, PU has poor resistance to ozone and UV, which can cause it to degrade over time.

10.Neoprene Rubber (CR)

Neoprene rubber is a synthetic rubber with excellent resistance to water, oil, and chemicals. It also has good mechanical properties such as high tensile strength and good abrasion resistance. However, neoprene rubber has poor resistance to UV and ozone, which can cause it to degrade over time.