For chemists, engineers, and procurement specialists in the B2B chemical sector, a thorough understanding of material properties is crucial. Hydroxy Terminated Polydimethylsiloxane, identified by CAS 70131-67-8, often referred to as OH Polymer or Hydroxyl Silicone Oil, is a fundamental siloxane fluid with unique chemical characteristics. As a leading manufacturer and supplier, we provide a technical overview to aid your selection and purchase decisions.

Chemical Structure and Synthesis

Hydroxy Terminated Polydimethylsiloxane is synthesized through the hydrolysis and condensation of dichlorodimethylsilane, with specific control over the termination process to introduce hydroxyl (-OH) groups at both ends of the polymer chain. The general formula can be represented as HO-[Si(CH₃)₂O]n-H. The variable 'n' dictates the molecular weight and consequently, the viscosity of the resulting fluid. Our manufacturing process ensures a consistent distribution of chain lengths and high purity, which are critical parameters for formulators.

Key Technical Specifications and Properties

When evaluating CAS 70131-67-8, consider the following technical aspects:

  • Appearance: Colorless and transparent liquid, indicating high purity.
  • Viscosity: Available in a range of viscosities, commonly from 20 cSt to over 100,000 cSt, depending on the degree of polymerization ('n'). This allows for precise formulation control.
  • Hydroxyl Content: The percentage of terminal OH groups varies with viscosity, influencing its reactivity in condensation reactions. Higher OH content typically corresponds to lower viscosity grades.
  • Thermal Stability: Exhibits excellent performance across a broad temperature range, typically -50°C to +250°C, with potential for higher short-term exposure depending on the grade.
  • Electrical Properties: Offers high dielectric strength, low dielectric loss, and excellent insulation resistance, making it ideal for electrical applications.
  • Chemical Inertness: Generally unreactive with most chemicals, except for strong acids, bases, and oxidizing agents.
  • Physical Properties: Low surface tension, good hydrophobicity, and low viscosity-temperature coefficient are also notable features.

Manufacturing Considerations and Quality Control

As a manufacturer, we emphasize stringent quality control at every stage of production. This includes precise control over monomer purity, polymerization conditions, and the termination reaction to achieve the desired viscosity and OH content. Post-production testing verifies purity, viscosity, and the absence of contaminants. For buyers, ensuring that your supplier maintains these standards is paramount to guarantee predictable performance in their own manufacturing processes. We offer detailed Technical Data Sheets (TDS) and Certificates of Analysis (CoA) for our Hydroxy Terminated Polydimethylsiloxane.

Why Source from Our China Facility?

Choosing us as your supplier for CAS 70131-67-8 means accessing high-quality OH Polymer manufactured under rigorous controls. We offer competitive pricing for bulk orders, ensuring cost-effectiveness for your industrial needs. Our experienced team is ready to assist with technical inquiries and provide samples for your evaluation. Contact us to learn more about our manufacturing capabilities and to discuss your specific requirements for Hydroxyl Silicone Oil.