Silicone elastomers/rubber - structure and
properties
Structure
Silicone polymer + filler + crosslinker (vulcanizing agent) = silicone
elastomer
Silicone elastomers are crosslinked linear silicone fluids or gums with a
three-dimensional structure.
Silicone elastomers contain fillers:
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Reinforcing fillers, like silica, which interact with the base polymer and
increase the strength of the elastomer
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Extending fillers, like quartz, diatoms, or metal oxides, which help reduce
the material’s cost
They also contain a crosslinker (vulcanizing agent).
Silicone elastomers differ from linear silicone fluids in three
ways
| Linear Polymers | Elastomers |
| Physical properties determined by chain length | Physical properties determined by degree of crosslinking |
| Linear polymers are liquids; viscosity increases with molecular
weight | Elastomers are solids with indefinite molecular weight |
| Soluble in solvents | Swell in solvents |
Properties
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Excellent high/low temperature performance capability (standard grades of
silicone elastomers can handle temperatures ranging from -40 to 200°C/-40 - to
392°F)
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Very flexible – flexibility virtually unaffected by temperature
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Excellent ozone resistance
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Excellent UV resistance
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Excellent electrical insulating properties
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High thermal conductivity
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Excellent resistance to a wide range of fluids and chemicals
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Excellent weatherability
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High gas and drug permeability
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Easy to fabricate/process
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Did You Know ... the source of silicone’s exceptional high and
low temperature performance capabilities is its low viscosity temperature
coefficient!
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Did you know ... there are six different ways silicone
materials can be cured!
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Get answers
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