Mingyi silicone（anhui）co,.ltd
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Poly dimethylsiloxane hydride terminated, commercially designated as IOTA 616, represents a crucial class of reactive silicone intermediates distinct from their methyl-terminated counterparts like IOTA 203. Characterized by the presence of highly reactive silicon-hydrogen (Si-H) bonds specifically located at the terminal ends of its polydimethylsiloxane (PDMS) chain, IOTA 616 is a tasteless, colorless transparent liquid offering unparalleled versatility in silicone chemistry.
The defining feature of IOTA 616 is its terminal Si-H functionality. This structure, represented by the general formula H-(CH<sub>3</sub>)<sub>2</sub>SiO-[(CH<sub>3</sub>)<sub>2</sub>SiO]<sub>n</sub>-Si(CH<sub>3</sub>)<sub>2</sub>H, makes it significantly more chemically active than silicone oils terminated with inert methyl groups. The terminal Si-H bonds are highly susceptible to reaction, particularly via hydrosilylation. This reaction, typically catalyzed by platinum complexes, involves the addition of the Si-H bond across unsaturated carbon-carbon bonds (like vinyl or allyl groups). Consequently, IOTA 616 serves as the fundamental building block for synthesizing a vast array of end-functional linear modified silicones.
IOTA 616 is available in a range of viscosities, correlating directly with molecular weight and inversely with active hydrogen content (H%):
| Viscosity (25°C, mPa·s) | Approx. Molecular Weight | Active H Content (%) | Density (g/cm³) | Refractive Index |
|---|---|---|---|---|
| 2-3 | 500-600 | 0.5 | 0.90 | 1.395 |
| 100 | 6,000 | 0.04 | 0.97 | 1.403 |
| 500 | 17,200 | 0.01 | 0.97 | 1.403 |
| 1000 | 28,000 | 0.007 | 0.97 | 1.403 |
| 10000 | 62,700 | 0.003 | 0.97 | 1.403 |
This viscosity range unlocks diverse applications:
Core Hydrosilylation Material: It is the essential starting material for producing numerous end-reactive silicones via hydrosilylation, forming Si-C linkages crucial for tailored properties.
Block Copolymer Synthesis: IOTA 616 acts as a key intermediate in creating silicone-organic block copolymers, enabling the combination of silicone properties (e.g., flexibility, thermal stability) with organic polymer characteristics.
Silicone Rubber Modification: Used as a chain extender in addition-cure Liquid Silicone Rubber (LSR) and as a crosslinker in addition-cure High-Temperature Vulcanizing (HTV) silicone rubber. Its incorporation significantly improves elongation at break, enhances toughness, and reduces the hardness of the final elastomer.
Polymer Modification: Serves as a vital starting material for modifying organic polymers (e.g., resins, plastics), imparting silicone-derived benefits like improved lubricity, release properties, weather resistance, or impact modification.
Moisture Protection: Similar to IOTA 202 and IOTA 203, lower viscosity grades can effectively form hydrophobic barriers for moisture-proofing applications.
In essence, IOTA 616's unique terminal Si-H reactivity makes it far more than just a silicone fluid. It is the indispensable reactive intermediate driving innovation across multiple industries, from high-performance elastomers and tailored silicone specialties to advanced polymer hybrids and protective coatings, leveraging its controllable molecular weight and reactive end groups for precise material engineering.
