Description

Chloropentamethyldisiloxane CAS NO 2943-62-6 is a versatile organosilicon compound, specifically a chlorinated disiloxane, that serves as a critical intermediate in silicone chemistry. Its value lies in its reactive chlorosilane group, which enables precise functionalization and chain extension in the synthesis of custom silicone polymers and fluids. This product is essential for manufacturers and R&D chemists in the silicone, pharmaceutical, and advanced materials sectors who require a reliable building block for creating tailored siloxane structures with specific properties.

Application

• Silicone Polymer Synthesis: A key monomer and chain-terminating agent for producing linear and branched polydimethylsiloxanes (PDMS) with controlled molecular weights.
• Surface Modification: Used to create hydrophobic coatings on glass, silica, and other inorganic surfaces via silanization reactions.
• Pharmaceutical Intermediates: Serves as a protected or functionalized synthon in the development of silicon-containing active pharmaceutical ingredients (APIs).
• Adhesive & Sealant Formulations: Acts as a cross-linking agent or adhesion promoter in high-performance silicone-based adhesives and sealants.
• Specialty Silicone Fluids: Employed in the manufacture of heat-transfer fluids, dielectric fluids, and release agents with specific thermal and chemical stability profiles.
• Research & Development: A fundamental reagent in academic and industrial labs for exploring new organosilicon compounds and materials.

Basic Information

Product Name	Chloropentamethyldisiloxane
CAS No.	2943-62-6
Molecular Formula	C5H15ClOSi2
Molecular Weight	182.80 g/mol
Synonyms	1-Chloro-1,1,3,3,3-pentamethyldisiloxane; Chloropentamethyl Disiloxane; (Chlorodimethylsilyloxy)trimethylsilane; Dimethyl(trimethylsiloxy)chlorosilane; Pentamethylchlorodisiloxane; Me5Si2OCl; HMDS-Cl (common abbreviation); Disiloxane, 1-chloro-1,1,3,3,3-pentamethyl-
EINECS	220-947-8

Quality Control

Our Chloropentamethyldisiloxane is produced under stringent quality management systems. Each batch undergoes rigorous analytical testing, including Gas Chromatography (GC) and NMR spectroscopy, to ensure high purity and consistency. A comprehensive Certificate of Analysis (COA) detailing identity, assay, and impurity profiles is provided with every shipment to support your quality assurance and regulatory compliance needs.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Due to its hygroscopic and moisture-sensitive nature, containers must be kept tightly sealed under an inert atmosphere (e.g., nitrogen or argon) to prevent hydrolysis and maintain product integrity.

Specification

Item	Specification
Appearance	Colorless to pale yellow clear liquid
Identification (IR)	Conforms to structure
Assay (GC)	≥ 98.0%
Density (at 25°C)	0.88 - 0.92 g/mL
Refractive Index (n20D)	1.3880 - 1.3920

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