In the "small-molecule hub" of the organosilicone industry chain, balancing boiling point and reactivity directly dictates suitability in cosmetic carriers, silicone capping, and vapor-phase deposition. Conventional dimethicone, with high molecular weight and poor volatility, fails as a lightweight carrier; while low-boil hydrogen-containing silicones are reactive, they are flammable, explosive, and skin-irritating, limiting personal care use. As demand rises for "low-boil, high-purity, chemically inert" small-molecule siloxanes in cosmetic volatiles, silicone rubber molecular weight control, and vapor-phase hydrophobing, sourcing Hexamethyldisiloxane (MM, (CH₃)₃Si–O–Si(CH₃)₃) with ≥99% purity and ~100℃ boiling point has become the core gap for domestic silicone basic feedstock localization.
Addressing this "low-boil capping" pain point,
Anhui IOTA Silicone Oil Co., Ltd. (IOTA) officially launches
Hexamethyldisiloxane IOTA 005 (MM, CAS 107-46-0, EINECS 203-492-7). Characterized by "colorless transparent liquid, ≥99% purity, 150kg/200L plastic/plastic-lined drums," and backed by "low-boil fast flash + inert siloxane backbone + high-purity low-impurity," it serves as the "small-molecule anchor" for cosmetic volatile silicones, silicone rubber capping agents, silazane synthesis feedstock, and vapor-phase hydrophobing agents.
Molecular Architecture: Hexa-Methyl Capped + Siloxane Bridge Low-Boil Logic
IOTA 005 structure: (CH₃)₃Si–O–Si(CH₃)₃, the simplest linear polysiloxane (MM):
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Hexa-Methyl Capped Inert Core: Both ends and backbone are fully methyl-capped (–CH₃), devoid of active functionalities (–H, –OH, –Cl). This full methylation grants extreme chemical inertness, thermal stability, and hydrophobicity, ensuring no reaction with actives (vitamins, antioxidants) and formulation stability.
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Low-Boil Fast-Flash Trait: Molecular weight only 162.38 g/mol, boiling point ~100℃. This makes it an ideal lightweight volatile carrier—spreads instantly on skin and flashes off, leaving no oily residue, providing immediate dry-feel superior to higher-boil solvents.
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Capping Agent & Synthon: In silicone rubber polymerization, MM acts as a chain transfer agent or capping agent to precisely control gum molecular weight, preventing processing difficulties from excessive viscosity. It is also a key precursor for Hexamethyldisilazane (HMDS), widely used in semiconductor cleaning and pharma synthesis.
Performance Leap: From "High-Visc Residue" to "Low-Boil Flash-Off"
Incorporating IOTA 005 enables qualitative leaps downstream:
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Cosmetic Lightweight Carrier: Replaces part of D5/D6 as volatile silicone in perfumes, antiperspirants, dry shampoos—delivers instant dry-feel with no residue; low surface tension lifts spreadability.
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Silicone MW Control: In HTV/RTV synthesis, acts as capping agent (0.5-3% of monomers) to tailor MW distribution, improving flow and extrusion while preventing scorch.
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Vapor-Phase Hydrophobing: Treats fumed silica, CaCO₃; methyl groups react with surface OH, imparting excellent hydrophobicity and improving dispersion in organic polymers.
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Analytical Solvent: Serves as GC stationary phase or analytical reagent for low-MW organics; inert solvent for organometallic reactions.
Application Penetration: From Cosmetic Mists to Chip Hydrophobing
IOTA 005 covers sectors doubly sensitive to "low-boil + inertness":
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Cosmetics: Perfumes, antiperspirants, dry shampoos, nail polishes, makeup removers (volatility aid).
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Silicone Synthesis: Capping agent/chain transfer agent for silicones, silicone oils, gums, resins; feedstock for HMDS.
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Electronics: Wafer cleaning, photoresist aid, chip package hydrophobing.
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Coatings & Inks: Leveling agent, defoamer, oleophobic coating additive.
IOTA Technical Guide: Explosion-Proof, Moisture-Sealed Handling
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Handling Environment: Low boiling point (~100℃), high vapor pressure. Operations require strict explosion-proof protocols, static grounding, no open flames. Use in fume hoods with solvent-resistant gloves/goggles.
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Capping Application: Add late in silicone polymerization (0.5-3% of monomers); adjust for target MW. Ensure anhydrous/anaerobic conditions to prevent MM hydrolysis/condensation.
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Hydrophobing Modification: Mix filler with MM (1:0.05-0.2 w/w); heat 80-120℃×2-4h, or soak ambient then bake to ensure surface OH reaction.
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Red Lines: Hazardous chemical (flammable liquid), 150kg/200L plastic/plastic-lined drums. Store cool (<30℃), dry, ventilated, away from ignition/heat; strictly sealed against moisture hydrolysis (forms trimethylsilanol); separate from oxidants, strong acids/bases; storage lighting/ventilation must be explosion-proof.
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Incompatibilities: Strictly prohibit contact with water, alcohols, acids, bases (triggers hydrolysis/violent reaction); avoid >150℃ baking (thermal decomposition); dispose waste as flammable organosilicone.
Industry experts note that under the "Dual Carbon" strategy and green transformation of fine chemicals, low-boil, high-purity small-molecule siloxanes are becoming critical links connecting upstream monomers to downstream high-value products. IOTA 005, with its "≥99% purity + fully methylated inert structure,"
fills the domestic supply chain gap for hexamethyldisiloxane in cosmetic carriers and silicone capping applications, providing reliable feedstock assurance for downstream process optimization and purity enhancement. This confirms domestic organosilicone basic feedstocks are advancing steadily along "purity elevation → application expansion → safety compliance," with growing technical command in critical fine chemical intermediates.
