Silicone oil typically refers to linear polysiloxane products that remain in a liquid state at room temperature, generally categorized into methyl silicone oil and modified silicone oil.

Methyl siloxane, commonly known as general-purpose silicone oil, has all its organic groups composed of methyl groups. Methyl silicone oil boasts excellent chemical stability, insulation properties, and hydrophobic performance. It is produced by hydrolyzing dimethyl dichlorosilane with water to form an initial polycondensation ring structure. The ring is then cracked and refined to obtain a low-ring structure. By combining the ring, end-capping agent, and catalyst, various polymerization degrees can be achieved. After vacuum distillation to remove low-boiling substances, silicone oil is produced.

Key features include heat resistance, electrical insulation, weather resistance, hydrophobicity, biological inertness, and a low surface tension. Additionally, silicon oil exhibits a low viscosity-temperature coefficient, high compressibility, and some varieties have radiation resistance properties.