Description

Polymethyloctadecylsiloxane is a high-molecular-weight organosilicon compound characterized by a siloxane backbone with pendant methyl and long-chain octadecyl (C18) groups. This unique structure provides exceptional lubricity, hydrophobicity, and thermal stability, making it a critical performance additive in demanding formulations. It is primarily utilized by manufacturers in the personal care, coatings, plastics, and specialty lubricants industries seeking to enhance surface properties, reduce friction, and improve water repellency.

Application

• Personal Care & Cosmetics: Acts as a premium emollient and conditioning agent in hair care products (shampoos, conditioners) and skin creams, providing a smooth, non-greasy feel and enhanced shine.
• Industrial & Metalworking Lubricants: Serves as a high-performance additive to reduce friction and wear in extreme-pressure lubricants and metalworking fluids.
• Plastics & Polymer Processing: Used as an internal and external lubricant and mold release agent to improve flow properties during extrusion and injection molding, and to aid in demolding.
• Coatings & Inks: Functions as a flow and leveling agent, slip additive, and mar-resistance aid to improve surface quality and performance in paints, varnishes, and printing inks.
• Textile & Fiber Treatment: Imparts durable water repellency (DWR) and softness to fabrics and non-woven materials.
• Adhesives & Sealants: Employed as a processing aid to control viscosity and improve surface release properties.

Basic Information

Product Name	Polymethyloctadecylsiloxane
CAS No.	68607-75-0
Molecular Formula	(C19H40OSi)n
Molecular Weight	Varies (Polymer)
Synonyms	Poly(methyloctadecylsiloxane); Methyloctadecylsiloxane homopolymer; Octadecylmethylsiloxane polymer; Poly(methyl stearyl siloxane); PMODS; Silicone oil, methyloctadecyl-; Stearyl methyl silicone; C18-alkyl modified silicone
EINECS	Contact for details

Quality Control

Our Polymethyloctadecylsiloxane is manufactured under a strict quality management system. Each batch undergoes rigorous analytical testing to ensure consistency in viscosity, purity, and functional performance, meeting the specifications required for industrial and cosmetic applications. Certificates of Analysis (COA) documenting key parameters are available upon request.

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.

Specification

Item	Specification
Appearance	Clear, colorless to pale yellow viscous liquid
Identification (IR)	Conforms to structure
Viscosity (25°C)	Specified grade (e.g., 100-5000 cSt)
Specific Gravity (25°C)	0.86 - 0.92
Refractive Index (25°C)	1.440 - 1.455
Assay (Active Content)	> 98.0%

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