Description

1,1,1,3,3-Pentamethyl-3-Acetoxydisiloxane is a specialized organosilicon compound, specifically a functional disiloxane, that serves as a versatile intermediate and capping agent in advanced material synthesis. Its core value lies in its unique bifunctional structure, featuring both hydrolyzable acetoxy groups and stable methyl groups, enabling precise control over polymer architecture and surface modification. This chemical is essential for R&D and production teams in the silicone polymer, coatings, and electronics industries seeking to tailor material properties such as hydrophobicity, adhesion, and thermal stability.

Application

• Silicone Resin & Polymer Modification: Acts as a chain terminator or cross-linking agent in the synthesis of specialty silicone resins, influencing molecular weight and branching.
• Surface Treatment & Coupling Agent: Used to modify inorganic surfaces (e.g., silica, glass) to impart hydrophobic or specific functional properties for composite materials.
• Adhesive & Sealant Formulations: Serves as a key ingredient in moisture-curable silicone adhesives and sealants, where the acetoxy group enables cross-linking upon exposure to atmospheric moisture.
• Release Coatings: Employed in the production of silicone-based release liners for labels, tapes, and industrial applications.
• Electronics Encapsulation: Used in formulating protective coatings and potting compounds for electronic components due to its good electrical insulation properties.
• Pharmaceutical & Cosmetic Intermediates: Functions as a synthetic intermediate for siloxane-based ingredients used in controlled drug delivery systems or personal care products.

Basic Information

Product Name	1,1,1,3,3-Pentamethyl-3-Acetoxydisiloxane
CAS No.	70693-47-9
Molecular Formula	C9H22O4Si2
Molecular Weight	250.44 g/mol
Synonyms	Acetoxy-terminated pentamethyldisiloxane; 3-Acetoxy-1,1,1,3,3-pentamethyldisiloxane; 1,1,1,3,3-Pentamethyl-3-(acetoxy)disiloxane; Acetic acid (1,1,1,3,3-pentamethyl-3-disiloxanyl) ester; Bis(trimethylsilyl) ether acetate derivative; PMDS-acetate; Acetoxypentamethyldisiloxane; Disiloxane, 1,1,1,3,3-pentamethyl-3-acetoxy-
EINECS	Contact for details

Quality Control

Our products undergo rigorous quality testing to ensure compliance with industry standards and batch-to-batch consistency. Quality assurance protocols include identity confirmation, purity assay, and control of key impurities. Certificates of Analysis (COA) detailing specific test results are available upon request to support your quality management and regulatory needs.

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). Due to its hygroscopic (moisture-sensitive) nature, containers must be kept tightly sealed under a dry inert atmosphere (e.g., nitrogen or argon) to prevent hydrolysis and degradation. Keep away from strong bases and oxidizing agents.

Specification

Item	Specification
Appearance	Colorless to pale yellow clear liquid
Identification (IR)	Conforms to structure
Assay (GC)	≥ 97.0%
Density (at 20°C)	~0.92 g/mL
Refractive Index (n20D)	~1.395
Water Content (KF)	≤ 0.1%

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