Description

Polydimethylsiloxane, Acetoxy Terminated is a reactive silicone polymer characterized by acetoxy end groups, which readily hydrolyze in the presence of atmospheric moisture to form a durable, flexible silicone sealant or adhesive. This chemical structure is critical for applications requiring rapid curing at room temperature with excellent adhesion to a wide variety of substrates. It is an essential raw material for formulators and manufacturers in the construction, automotive, and electronics industries seeking reliable, one-component, moisture-curing systems.

Application

• Room Temperature Vulcanizing (RTV) Silicone Sealants: Primary base polymer for one-part, acetoxy-cure sealants used in construction glazing, sanitary ware, and general assembly.
• Industrial Adhesives & Potting Compounds: Used in formulating adhesives for bonding metals, glass, ceramics, and many plastics, as well as for potting and encapsulating electronic components.
• Automotive Gasketing & Form-in-Place (FIP) Gaskets: Serves as a key ingredient for gaskets and formed seals in engines, transmissions, and electronic control units.
• Mold Making & Prototyping: Employed for creating flexible molds for casting resins, plasters, and low-melt metals due to its excellent release properties and dimensional stability.
• Waterproofing & Protective Coatings: Formulated into coatings for protecting concrete, masonry, and other porous materials from water ingress and environmental degradation.
• Electrical Insulation: Provides dielectric insulation and environmental protection for wires, connectors, and other electrical assemblies.

Basic Information

Product Name	Polydimethylsiloxane, Acetoxy Terminated
CAS No.	68440-60-8
Molecular Formula	(C2H6OSi)n • C4H6O4Si
Molecular Weight	Varies by chain length (n)
Synonyms	Acetoxy-Terminated Polydimethylsiloxane; Acetoxy-Functional Silicone Fluid; α,ω-Diacetoxypolydimethylsiloxane; Acetoxy Silicone Polymer; RTV Silicone Gum; One-Part RTV Silicone Base Polymer; Moisture-Curing Silicone Prepolymer; Dimethyl Silicone Fluid, Acetoxy End-blocked
EINECS	Contact for details

Quality Control

Our Polydimethylsiloxane, Acetoxy Terminated is manufactured under a strict quality management system. Each batch is tested to ensure consistent performance in viscosity, cure rate, and mechanical properties. Certificates of Analysis (COA) documenting key parameters such as viscosity, acetoxy content, and volatile matter are available upon request to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. This material is hygroscopic (moisture-sensitive) and must be stored in a cool, dry place at 15-25°C. Containers must be kept tightly sealed to prevent premature cross-linking due to atmospheric moisture. Store away from strong acids and organic solvents.

Specification

Item	Specification
Appearance	Clear, colorless to pale yellow viscous fluid
Identification (IR)	Conforms to structure
Viscosity (25°C)	Specified grade (e.g., 10,000 - 100,000 mPa·s)
Acetoxy Content	As specified
Volatile Matter	≤ 1.0%
Cure Time (Skin-Over)	3 - 20 minutes (varies with grade & conditions)

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