In organosilicon prepolymerization and polymer modification, traditional vinyl double end-blockers provide terminal vinyls but rely on platinum-catalyzed hydrosilylation, limiting activity in platinum-free or high-temp vulcanization systems; common vinyl-terminated silicone oils have high viscosity, causing uneven dispersion and mixing heat in low-MW prepolymers; methoxy end-blockers hydrolyze too fast with narrow operation window, risking premature gelation; hydride silicone oils require unsaturated alkenes and platinum, reducing formulation freedom. For specifications demanding "ethoxy end-group, low-viscosity easy dispersion, controllable hydrolysis crosslinking, vinyl double end-blocker replacement", a strictly controlled ethoxy-terminated low-viscosity silicone oil places room-temperature crosslinkable activity and process tolerance at one raw-material node. Addressing this, Anhui IOTA Silicone Oil Co., Ltd. launches Low Viscosity Vinyl Silicone Oil IOTA-218. Characterized by "CAS 26710-23-6; ethoxy-terminated low-MW linear polydimethylsiloxane, oily liquid, easily hydrolyzes and crosslinks producing ethanol; appearance colorless transparent liquid; viscosity (20℃) 10-20mPa·s; flash point ≥61℃; volatile (105℃,2h) ≤0.1%; applications: raw rubber prepolymer replacing traditional vinyl double end-blocker, high-temp vulcanizing silicone rubber (HTV) base material main raw material, PU/acrylic modifier (improving weather/aging/UV/cracking resistance/toughness), addition liquid silicone rubber and silicone gel main material; packaging IBC tote 1000kg, 200L iron/plastic drum 200kg, 25L plastic drum 25kg, custom; non-hazardous storage/transport; stable at room temp, no open flame or water contact, ventilated dry, sun/rain protected; original sealed shelf life 1 year from production, retest required after expiry; brand IOTA", backed by "ethoxy end-cap + low-vis fast mix + controllable hydrolysis", it serves as an alkoxy active intermediate for silicone prepolymerization and polymer modification. System Positioning: Ethoxy-Terminated Silicone Oil Among Active End-Blocker Families Within active silicone end-blocker families, IOTA-218 is an ethoxy-terminated low-viscosity linear PDMS, distinct from traditional vinyl double end-blockers (platinum-dependent, no hydrolytic self-crosslinking), vinyl-terminated silicone oils (require hydride crosslinker, process bound to Pt), hydride silicone oils (Si–H crosslinking, H₂ byproduct risks foaming in PU), and hydroxy-terminated silicone oils (condensation needs dehydration, slow). IOTA-218 uses ethoxy end-groups that hydrolyze to silanols in presence of moisture, enabling self-condensation or reaction with other silanols/isocyanates, positioning as a shared hydrolyzable active carrier for "HTV prepolymer, PU/acrylic modification, addition LSR/gel", rather than a mere diluent or inert end-capper. Molecular Architecture: Bis-Ethoxy End + Dimethylsiloxane Short Chain + Low Viscosity Fast Penetration + Hydrolysis Yields Alcohol IOTA-218 is a short-chain linear PDMS with ethoxy (–OCH₂CH₃) terminals. Under trace moisture or acid/base, ethoxy groups hydrolyze to silanols (Si–OH) releasing ethanol, which further condenses into Si–O–Si networks; viscosity 10-20mPa·s (20℃) enables rapid uniform mixing with fillers, resins and gums; volatile ≤0.1% (105℃,2h) minimizes bubbles in high-temp processing; flash point ≥61℃ gives basic handling safety; colorless transparent oily liquid with good compatibility to organic solvents and polymers; ethanol byproduct is relatively low-toxic and volatile, safer and more controllable than chlorosilanes or methoxy systems. Performance Leap: From "Pt-Dependent, Hard Mix, Fast Gel" to "Ethoxy End-Cap, Low-Vis Fast Polymerization" With IOTA-218, prepolymerization and modification improve jointly: prepolymer substitution—replaces traditional vinyl double end-blockers via hydrolytic crosslinking without platinum, lowering cost and process constraints; HTV base material—low viscosity improves filler and additive dispersion, raising mixing efficiency and compound uniformity; polymer modification—for PU and acrylic, ethoxy groups react with NCO or hydroxyl to boost weather/aging/UV/cracking resistance and toughness; addition LSR and gel—serves as main material with low volatile ensuring low shrinkage and few bubbles; process tolerance—moderate hydrolysis rate gives wider operation window than methoxy end-blockers, suitable for batch production. Application Penetration: From Raw Rubber Prepolymer to HTV, PU Modification and Addition Silicone IOTA-218 covers four core scenarios. Raw rubber prepolymer: replaces traditional vinyl double end-blocker in silicone gum synthesis—emphasizing Pt-free hydrolytic crosslink and easy mixing; trial by prepolymer target. HTV base material: main raw material for HTV compounding—emphasizing filler dispersion and uniformity; trial by rubber hardness/strength. PU/acrylic modification: improves weather/aging/UV/toughness—emphasizing ethoxy reaction with NCO/hydroxyl; trial by resin type. Addition LSR and silicone gel: main material for crosslink network—emphasizing low volatile and controllable cure; trial by curing condition. ⚠️ Taboo: no open flame or water contact during storage/use; ventilated dry, sun/rain protected; original sealed container at room temp; retest after 1-year shelf life; non-hazardous transport. IOTA Technical Guide: Moisture-Proof Seal, Low-Vis Prepolymer, Non-Haz Transport IOTA-218 is a colorless transparent oily liquid in IBC totes (1000kg), 200L drums (200kg), 25L pails (25kg), custom available. As prepolymer or modifier, mix with other components in dry environment to avoid premature hydrolysis gel; specific dosage by target crosslink density and modification degree via trial. Store at room temp in dry ventilated place, sealed container, no open flame or water; non-hazardous storage and transport; shelf life 1 year in original package, retest qualified for extended use. Industry Insight: Alkoxy end-blocker selection is not the lower viscosity the better, but using terminal alkoxy for hydrolysis rate and crosslink mechanism, viscosity for dispersion efficiency and filler wetting, volatile content for high-temp bubble risk, and storage stability for batch shelf life. For engineers of silicone gum, HTV, modified resins and addition silicones, IOTA-218 uses one CAS 26710-23-6, 10-20mPa·s, ≤0.1% volatile ethoxy-terminated low-vis silicone oil across prepolymer, HTV, PU/acrylic modification and liquid silicone, taking ethoxy activity, low-vis fast polymerization and controllable hydrolysis as batch-checkable anchors, securing designable routes and process tolerance.