Description

Octadecamethyloctasiloxane is a high-purity, linear organosilicon compound belonging to the polydimethylsiloxane (PDMS) family. This versatile silicone fluid is valued for its excellent thermal stability, low surface tension, and inert chemical properties, making it a critical intermediate and functional additive. It is essential for manufacturers in the personal care, industrial lubricant, and specialty chemical sectors seeking reliable performance and formulation consistency.

Application

• Personal Care & Cosmetics: Acts as a primary emollient, skin-conditioning agent, and carrier fluid in antiperspirants, deodorants, skin creams, and sun care products, providing a smooth, non-greasy feel.
• Industrial Lubricants & Release Agents: Serves as a base fluid or additive in high-temperature lubricants, mold release agents for plastics and rubber, and anti-foaming agents in various industrial processes.
• Chemical Intermediate: Used as a key building block (chain extender or endblocker) in the synthesis of higher molecular weight silicone polymers, resins, and modified silicones.
• Electrical & Thermal Fluids: Employed in dielectric cooling fluids and heat transfer fluids due to its high thermal stability and electrical insulating properties.
• Polishing & Coating Additives: Incorporated into automotive and furniture polishes, as well as protective coatings, to enhance gloss, water repellency, and leveling.
• Textile & Fiber Treatment: Functions as a softener and water repellent finish for fabrics and non-woven materials.

Basic Information

Product Name	Octadecamethyloctasiloxane
CAS No.	556-69-4
Molecular Formula	C18H54O7Si8
Molecular Weight	577.25 g/mol
Synonyms	Octamethyltrisiloxane; PDMS 8; Linear Octamer; Dimethyl Siloxane Octamer; Polydimethylsiloxane, n=8; Decamethyltetrasiloxane (common misnomer); Silicone Fluid 556-69-4; D8 (in silicone notation)
EINECS	209-136-7

Quality Control

Our Octadecamethyloctasiloxane is produced under a strict quality management system. Each batch undergoes comprehensive analytical testing, including assay, identity confirmation, and impurity profiling, to ensure it meets precise specifications for industrial and cosmetic applications. Certificates of Analysis (COA) documenting purity, viscosity, and other critical parameters are available upon request to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Keep away from strong oxidizing agents and open flames. Under recommended storage conditions, the product remains stable for an extended period.

Specification

Item	Specification
Appearance	Colorless clear liquid
Identification (IR)	Conforms to standard
Assay (GC)	≥ 98.0%
Refractive Index (20°C)	1.398 - 1.402
Density (20°C)	0.95 - 0.97 g/cm³
Viscosity (25°C)	8 - 12 cSt
Water Content (KF)	≤ 0.05%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.