In addition-cure organosilicon synthesis, relying only on high-molecular vinyl-terminated fluids makes low-MW regulation inflexible and end-group equivalence hard to calculate; single-vinyl end-blockers introduce one terminal only, requiring extra steps for linear bis-vinyl chains; side-chain vinyl cyclics raise vinyl content but leave terminal structure undefined, causing scattered platinum hydrosilylation sites and uncontrolled hardness/tear; impure ligands for platinum complexes cause unstable catalyst activity and poor batch repeatability. For specifications demanding "dual-terminal vinyl, low-MW stoichiometric, high-purity low-impurity, end-blocker plus platinum-ligand precursor", a strictly controlled vinyl double end-blocker places molecular end-design and catalytic intermediate at one raw-material node. Addressing this, Anhui IOTA Silicone Oil Co., Ltd. launches Tetramethyl Divinyl Disiloxane IOTA-1002. Characterized by "chemical name tetramethyl divinyl disiloxane; alias vinyl double end-blocker; CAS 2627-95-4; EINECS 220-099-6; formula [(CH₃)₂C₂H₃Si]₂O or C₈H₁₈OSi₂; MW 186.4; structure Si–O–Si with one vinyl and two methyls per terminal silicon; colorless transparent liquid; boiling point 133-139℃; density 0.818g/cm³; refractive index 1.4118-1.4123; purity 99.5%; vinyl content 29.0%; water-insoluble; for addition silicone rubber, silicone gel, liquid silicone rubber, vinyl silicone resin, vinyl silicone oil, platinum complex as additive/intermediate; 20kg plastic drum, 160kg iron drum, custom packing available; store in cool dry ventilated warehouse, transport as dangerous goods; brand IOTA", backed by "dual-terminal vinyl + low-MW stoichiometry + high-purity low-impurity", it serves as a bis-vinyl end-blocking intermediate for addition silicones and platinum systems. System Positioning: Vinyl Double End-Blocker Among Vinyl Capping Families Within vinyl capping agents, IOTA-1002 is a bis-vinyl disiloxane low monomer, distinct from hexamethyldisiloxane (no vinyl, inert chain stopper), mono-vinyl end-blockers (single-end introduction, multiple steps for bis-linear), side-chain vinyl cyclics (side unsaturation, undefined terminals), and high-MW vinyl-terminated fluids (finished polymer, not for low-MW capping). IOTA-1002 offers two terminal vinyls at fixed MW 186.4 for calculable bifunctional equivalence, positioning as a universal定点 intermediate for "ring-opening equilibrium capping, vinyl silicone oil/rubber/gel/resin synthesis, platinum complex ligand precursor", rather than a mere crosslinker or inert diluent. Molecular Architecture: Si–O–Si Core + Bis-Vinyl + Tetramethyl Symmetric + Low-Boil Processable IOTA-1002 structure (CH₃)₂(CH₂=CH)Si–O–Si(CH=CH₂)(CH₃)₂ places one vinyl and two methyls on each terminal silicon. Both terminal vinyls undergo platinum-catalyzed hydrosilylation with Si–H of hydride fluids; only two reactive sites enable predetermined substitution and chain length. Tetramethyl symmetry gives low polarity, RI 1.4118-1.4123, density 0.818g/cm³, compatible optically and rheologically with PDMS; MW 186.4 and vinyl 29.0% make molar vinyl equivalence explicit; boiling 133-139℃ enables vacuum recovery and unreacted monomer removal; purity 99.5% and water insolubility reduce moisture interference on platinum catalysis and ring-opening equilibrium. Performance Leap: From "Undefined Terminals, Hard Equivalence" to "Bis-Vinyl Fixed, Low-MW Constructable" With IOTA-1002, addition silicone synthesis improves jointly: stoichiometric capping—bis-vinyl reacts near 1:1 with cyclic/linear siloxane feeds under acid or base equilibrium to control polymer length and terminal vinyl mole fraction, narrowing MW distribution; vinyl tuning—adding double end-blocker raises terminal vinyl without side branching, so platinum/hydride systems can design crosslink density, hardness and tear by vinyl–Si–H equivalence; silicone gel—low-MW bis-vinyl builds low-modulus, high-transparency, adjustable-softness encapsulation networks; vinyl resin—terminal/co-vinyl units reserve sites for thermal or addition curing in coatings, insulation and reinforcement; platinum complexes—bis-vinyl acts as ligand precursor, with high purity supporting active and consistent catalyst mother liquor. Application Penetration: From LSR Base Gum to Gel, Resin and Platinum Complex IOTA-1002 covers six core scenarios. Addition silicone rubber and LSR: end-capper to adjust base gum vinyl content and MW, with hydride crosslinker for cure network; trial by target vinyl mole fraction. Silicone gel: low-modulus electronic/optical potting with controlled softness and clarity; trial by gel crosslink density. Vinyl silicone oil: ring-opening equilibrium to vinyl-terminated PDMS for further modification or addition formulations; trial by target viscosity. Vinyl silicone resin: introduce terminal/co-vinyl units for coatings, electrical insulation, reinforcing resin; trial by M/Q and vinyl ratio. Platinum complexes: vinyl ligand precursor for platinum catalyst preparation; trial by catalytic process. ⚠️ Taboo: store in cool dry ventilated warehouse; transport/storage as dangerous goods; away from fire/heat and strong oxidizers/acids/bases; avoid sulfur/phosphorus/nitrogen/heavy-metal impurities that may poison platinum. IOTA Technical Guide: Dose by Vinyl Equivalence, Split Ring-Opening/Addition, Hazardous Storage IOTA-1002 is a colorless transparent liquid in 20kg plastic drums, 160kg iron drums, custom packing available. For ring-opening equilibrium of vinyl-terminated oil, calculate molar ratio of double end-blocker to cyclic/dimethylsiloxane feed for target MW, run acid or base equilibrium, then devolatilize; in addition formulations, set crosslink density by terminal vinyl versus hydride Si–H equivalence via trial; for platinum complexes, feed per catalyst process. Store in cool dry ventilated warehouse, sealed; transport as dangerous goods, away from ignition, heat and oxidizers. Industry Insight: Vinyl end-blocker selection is not the more vinyl the better, but using terminal count for mono/bis design, low-MW equivalence for molecular-weight distribution, purity for platinum stability, and boiling point for devolatilization/recovery. For silicone rubber, oil, resin and catalyst engineers, IOTA-1002 uses one CAS 2627-95-4, 99.5% purity, 29.0% vinyl bis-terminal low monomer across LSR, gel, vinyl oil, vinyl resin and platinum complexes, taking defined terminals, calculable equivalence and batch purity as checkable anchors, securing designable addition formulations and reproducible performance.