[R2SiO]n
ChemistrySilicone is specified as [R2SiO]n. Density band ~1.1–1.5 g/cm³.
Darker cells mean a higher score for this topic on that metric.
Strength28
Heat resistance80
Fire performance62
Insulation42
Workability76
Circularity40
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Last reviewed Sources & creditsMedia creditsMethodology
Quick answers
Is Silicone non-combustible?
Declared reaction class in this atlas: often high LOI vs organic rubbers. Assemblies still need resistance tests.
Does Silicone insulate?
Thermal mark 42/100 versus the atlas. Conductivity note: ~0.2 W/m·K; filled greases conduct.
What is the density band?
~1.1–1.5 g/cm³
How is it made?
Origin story: Kipping / Rochow 1940s (United Kingdom / US).
Can it be recycled?
Circularity mark 40/100 — editorial, route-specific.
Typical melting or failure heat?
elastomer; resins cure
heat 80 · fire 62
What holds Silicone together is not the nickname. Formula [R2SiO]n, density ~1.1–1.5 g/cm³.
Meters are atlas-relative. Grades are the SKUs buyers write.
Phases
Microstructure
OrderProcessing sets grain, crystallinity or fibre orientation — the reason two lots of Silicone can test differently.
Interfaces
SurfacesCoatings, oxide films, sizings or paper faces often decide weather and fire behaviour more than the bulk brochure.
Defects
FlawsInclusions, voids, knots, pinholes or residual stress start the failures that mill certificates do not list.
Grades
VariantsSilicone is a family. Grade names below are the ones buyers actually write on RFQs.
Ageing
TimeMoisture, UV, creep, hydrogen or carbonation shift properties in service. Design to the aged state.
Relative meters
Strength28
Strength is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Heat envelope80
Heat envelope is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Fire behaviour62
Fire behaviour is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Insulation42
Insulation is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Workability76
Workability is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Circularity40
Circularity is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Grades
VMQ
Vinyl methyl gum.Vinyl methyl gum.
LSR
Liquid two-part.Liquid two-part.
RTV-1
Acetoxy/oxime sealants.Acetoxy/oxime sealants.
Resin MQ
High-temp coatings.High-temp coatings.
Medical USP
Implant vs short-term grades.Implant vs short-term grades.
Bonds
Primary bonding
Silicone holds together by covalent chain chemistry.
Secondary forces
Hydrogen bonds, van der Waals stacks or grain-boundary cohesion set toughness and moisture uptake.
Composites & fills
Fillers, fibres, plasticisers or aggregates are part of the real product, not impurities.
Environment film
Oxides, chars, sizings or paints are the layer the world actually meets.
Change the grade, the coating or the moisture and you have a different material with the same English name.
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