Description

Polydimethylsiloxane, Dihydroxy Terminated is a reactive silicone polymer featuring hydroxyl (-OH) groups at both chain ends, making it a versatile intermediate for further chemical synthesis. This bifunctional structure is critical for creating custom silicone networks, elastomers, and copolymers with tailored properties. It is essential for formulators and manufacturers in the adhesives, sealants, coatings, and personal care industries seeking to enhance product performance, flexibility, and durability.

Application

• Silicone Elastomer & Rubber Precursor: Acts as a key intermediate in the production of room-temperature-vulcanizing (RTV) and high-temperature-vulcanizing (HTV) silicone rubbers.
• Adhesive & Sealant Formulation: Used as a base polymer or reactive modifier in silicone-based adhesives, sealants, and potting compounds, contributing to weatherability and flexibility.
• Copolymer Synthesis: Serves as a macromonomer for creating silicone-organic hybrid polymers, such as silicone polyethers or silicone polyesters, used in surfactants and foam control agents.
• Release Coatings & Molding: Employed in the formulation of non-stick release coatings for papers, films, and industrial molding applications.
• Personal Care & Cosmetic Ingredients: Utilized as a starting material for synthesizing silicone derivatives that provide emolliency, gloss, and conditioning in skincare and haircare products.
• Textile & Fiber Treatment: Imparts softness, lubricity, and water repellency to fibers and fabrics.
• Lubricant & Grease Additive: Functions as a base fluid or thickener for specialty high- and low-temperature lubricants.
• Pharmaceutical & Medical Device Components: Used in the synthesis of biocompatible silicone materials for controlled drug delivery systems and medical-grade tubing.

Basic Information

Product Name	Polydimethylsiloxane, Dihydroxy Terminated
CAS No.	70131-67-8
Molecular Formula	CnH2n+6O3Sin (n = variable)
Molecular Weight	Varies by chain length (Viscosity Grade). Contact for details.
Synonyms	α,ω-Dihydroxypolydimethylsiloxane; Dimethyl Silicone Diol; Hydroxy-Terminated Polydimethylsiloxane; PDMS Diol; Polydimethylsiloxane Diol; OH-Terminated PDMS; Bis(hydroxyalkyl)-terminated polydimethylsiloxane; Silicone Fluid, Dihydroxy Terminated
EINECS	Contact for details.

Quality Control

Our Polydimethylsiloxane, Dihydroxy Terminated is manufactured under a strict quality management system. Each batch undergoes rigorous analytical testing to ensure consistency in hydroxyl value, viscosity, molecular weight distribution, and purity. Certificates of Analysis (COA) detailing key specifications are provided with every shipment to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Keep away from strong acids, bases, and oxidizing agents. Under recommended storage conditions, the product is stable for at least 24 months from the date of manufacture.

Specification

Item	Specification
Appearance	Colorless to pale yellow clear viscous liquid
Identification (IR)	Conforms to structure
Viscosity (25°C)	Grade dependent (e.g., 100 - 100,000 cSt)
Hydroxyl Value	As per grade (Typical range: 0.1 - 1.0 meq/g)
Water Content	< 0.1 % (Karl Fischer)
Volatile Matter	< 1.0 %
Acidity (as HCl)	< 0.01 %

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