Advanced Topic 642 of 1102 Inorganic Chemistry
Silicones
Polymers with Si-O backbone and organic side groups, valued for heat and water resistance.
In-depth explanation of Silicones
Silicones are polymers with a backbone of alternating silicon and oxygen atoms, -Si-O-Si-, and organic groups such as methyl on each silicon, giving the general formula (R2SiO)n. The strong Si-O bond and flexible backbone keep silicones stable over a wide range, roughly -50 to 250 degrees C for common rubbers. The organic groups make them water repellent and chemically inert. They are made by hydrolysing dimethyldichlorosilane and then polymerizing the siloxanes. Depending on cross-linking they form oils, greases, elastomers and resins.
Going deeper: Silicones
Key ideas: Polymers with Si-O-Si backbone and organic groups, repeating unit R2SiO. Made by hydrolysis of R2SiCl2 from the Rochow direct process (Si + 2CH3Cl with Cu catalyst). Chain length controls form: short fluids, long rubbers, crosslinked resins from RSiCl3. They are water repellent, heat stable from about -50 to 250 C, and biocompatible; used in sealants, lubricants and implants.
Common mistakes and connections: Students confuse silicone with silicon, the element. Chain ends are capped with R3SiCl, and trichloride units cause crosslinks, while only dichloride gives linear chains. The Si-O bond is strong and the Si-O-Si angle is flexible, giving rubbery behavior. Links to polymers, organosilicon chemistry and hydrolysis of chlorides.
Visualization of Silicones
Silicones form by condensation of hydrolysed dimethyldichlorosilane, building long -Si-O-Si- chains with organic side groups. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Silicone rubber stays flexible well below freezing and also at temperatures above 200 degrees C.
Frequently asked questions about Silicones
What is Silicones?
Polymers with Si-O backbone and organic side groups, valued for heat and water resistance.
Is Silicones a beginner, intermediate or advanced topic?
Silicones is a advanced topic in Inorganic Chemistry. It builds on beginner and intermediate topics, so review those first if needed.
What should I learn before Silicones?
Study these earlier topics in Inorganic Chemistry first: Carbon Family, Silicon Chemistry, Silicates.
What comes after Silicones?
The next topics in Inorganic Chemistry are Glass and Carbon Oxides.
Can I practise Silicones with quizzes?
Yes. The interactive lesson includes a self-check question on Silicones, and the Inorganic Chemistry quiz draws on every topic in this area.
Where Silicones fits in Inorganic Chemistry
Silicones is topic 27 of 113 in Inorganic Chemistry.