Description

1,17-Dihydroxy Octadecamethyl Nonasiloxane is a linear, hydroxyl-terminated polydimethylsiloxane (PDMS) oligomer, a key member of the silicone family. This bifunctional silanol is a versatile chemical intermediate prized for its ability to modify polymer backbones and impart unique surface-active properties. It is essential for manufacturers in the personal care, coatings, and specialty materials sectors seeking to enhance product performance, durability, and feel.

Application

• Silicone Resin & Polymer Modification: Acts as a chain extender or cross-linking agent in the synthesis of silicone resins, rubbers, and high-consistency elastomers.
• Surface Treatment & Coatings: Used as a precursor for creating water-repellent, anti-adhesive, and release coatings for textiles, paper, and industrial molds.
• Personal Care & Cosmetics: Serves as a building block for silicone copolymers used in hair conditioners, skin care products, and antiperspirants to improve spreadability and silky feel.
• Adhesives & Sealants: Functions as a reactive intermediate to improve the flexibility, adhesion, and weather resistance of silicone-based adhesive formulations.
• Lubricants & Greases: Employed in the formulation of high-performance silicone lubricants and greases for extreme temperature applications.
• Pharmaceutical & Medical Devices: Utilized in the production of silicone components where precise molecular weight and reactive end groups are critical for biocompatibility.

Basic Information

Product Name	1,17-Dihydroxy Octadecamethyl Nonasiloxane
CAS No.	18678-58-5
Molecular Formula	C18H58O11Si9
Molecular Weight	667.4 g/mol
Synonyms	α,ω-Dihydroxypolydimethylsiloxane (n=9); Polydimethylsiloxane, dihydroxy terminated (MW ~667); Hydroxyl-terminated PDMS (9 repeating units); Silanol-terminated decamethylnonasiloxane; Bis(hydroxy)octadecamethylnonasiloxane; Linear OH-PDMS; Dihydroxyfunctional silicone fluid; Reactive silicone oil
EINECS	Contact for details

Quality Control

Our 1,17-Dihydroxy Octadecamethyl Nonasiloxane is produced under stringent quality management systems. Each batch undergoes rigorous analytical testing to ensure consistency in molecular weight, hydroxyl value, and purity. Certificates of Analysis (COA) detailing key specifications such as assay, viscosity, and water content 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, and well-ventilated area at room temperature (15-25°C). This material is hygroscopic (moisture-sensitive) and should be kept under a dry inert atmosphere (e.g., nitrogen) for long-term storage to prevent condensation and polymerization. Keep away from strong acids, bases, and oxidizing agents.

Specification

Item	Specification
Appearance	Colorless to pale yellow clear liquid
Identification (IR)	Conforms to structure
Assay (by OH value)	≥ 95.0 %
Viscosity @ 25°C	Contact for details
Water Content (Karl Fischer)	≤ 0.1 %
Molecular Weight (GPC)	~ 667 g/mol (n=9)

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