OH-85 Hydroxy-Terminated Polymethylhydrogensiloxane
Silico® OH-85 Hydroxy-Terminated Polymethylhydrogensiloxane (HT-PMHS), CAS No. 63148-57-2, is a low-viscosity silicone fluid with hydroxyl ends and reactive Si-H bonds. It’s used in crosslinking, hydrosilylation, and water-repellent coatings, known for stability and low surface energy.
Product Introduction:
This fluid is part of the functional silicone oils family, valued for its reactivity, thermal stability, and low surface energy. It plays a key role in formulating water-repellent coatings, addition-cure silicone rubbers, and release agents.
Technical Specifications
| Parameter | Typical Value |
|---|---|
| Chemical Name | Hydroxy-Terminated Polymethylhydrogensiloxane |
| CAS Number | 63148-57-2 |
| INCI Name | Polymethylhydrogensiloxane (hydroxy-terminated) |
| Appearance | Colorless to slightly yellow transparent liquid |
| Viscosity (@25 °C) | 15–40 mPa·s |
| Density (@25 °C) | ~1.006 g/cm³ |
| Refractive Index (nD @20 °C) | ~1.382 |
| Flash Point (Closed Cup) | >204 °C |
| Solubility | Soluble in hydrocarbons; insoluble in water |
| Storage Conditions | Store in cool, dry place below 30 °C |
Key Features & Functional Benefits
High Reactivity: Contains both hydroxyl and Si-H groups for crosslinking and grafting
Hydrophobic Coating Agent: Imparts excellent water repellency to porous materials
Thermal and Chemical Stability: Suitable for long-term use in harsh conditions
Low Surface Tension: Promotes wetting, spreading, and uniform coating
Customizable Molecular Weight: Available in various chain lengths for targeted performance
Applications & Use Cases
Hydroxy-Terminated Polymethylhydrogensiloxane is widely used across industries such as:
✔ 1. Waterproofing Agent
Hydrophobization of concrete, ceramics, textiles, and leather
Durable treatment for exterior coatings and porous substrates
✔ 2. Crosslinking Intermediate
Acts as a crosslinker in addition-cure RTV silicone rubber systems
Enhances mechanical strength and thermal resistance in cured elastomers
✔ 3. Release Agent
Effective in injection molding and rubber demolding
Reduces surface adhesion in thermoplastics and PU systems
✔ 4. Chemical Reducing Agent
Used in organic synthesis (especially in selective reductions via Si-H)
Packaging Options
1 kg bottles for lab and R&D use
20 kg pails and 200 kg drums for industrial bulk applications
1000 kg IBC containers for large-scale production
All technical data provided is based on current knowledge and experience. Users must test product suitability for intended applications.
No warranties are expressed or implied. Silico® assumes no liability for incidental or consequential damages.
Jessica G.
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