| HS Code | 306766 |
| Productname | Vinyl Silicone Oil RH-Vi306 |
| Chemicalname | Vinyl-terminated polydimethylsiloxane |
| Casnumber | 68083-19-2 |
| Appearance | Colorless transparent liquid |
| Color | ≤20 APHA |
| Viscosityat25c | 3000 mPa·s (typical) |
| Vinylcontent | 0.6 wt% (typical) |
| Specificgravityat25c | 0.97-0.98 |
| Refractiveindexat25c | 1.403-1.406 |
| Volatilematter | ≤2.0% (150 °C, 3 h) |
| Flashpoint | ≥300 °C |
| Acidvalue | ≤0.05 mg KOH/g |
| Storagetemperature | 5-30 °C |
| Shelflife | 12 months |
As an accredited Vinyl Silicone Oil RH-Vi306 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Vinyl Silicone Oil RH-Vi306 is supplied in 200 kg steel drums, with inner plastic liners for safe transport and storage. |
| Container Loading (20′ FCL) | Vinyl Silicone Oil RH-Vi306 is securely loaded and sealed in a 20-foot FCL container for safe international shipment. |
| Shipping | Vinyl Silicone Oil RH-Vi306 is shipped in sealed, labeled drums or IBCs. Keep containers closed, dry, and protected from moisture, contamination, and extreme temperatures. Transport as non-hazardous unless the SDS or local regulations state otherwise, following all applicable handling requirements. |
| Storage | Store Vinyl Silicone Oil RH-Vi306 in a cool, dry, well-ventilated area, away from direct sunlight, heat, sparks, and open flames. Keep containers tightly closed, properly labeled, and only in original or compatible containers. Avoid strong oxidizers, acids, alkalis, moisture, and contamination. Use secondary containment, inspect for leaks, and follow local regulations. |
| Shelf Life | Store in a cool, dry, well-ventilated place in sealed original containers; typical shelf life is 12 months from date of manufacture. |
Addition-cure liquid silicone rubber compounds are processed through water-cooled barrels and closed-loop static mixers before entering a heated mold; RH-Vi306 is introduced as a low-viscosity vinyl-functional silicone oil to reduce mixed-part viscosity and permit injection into multi-cavity tools without sacrificing the flash-free cure expected from platinum hydrosilylation. The formulation addition ratio is controlled by the total silicon hydride to vinyl molar balance, not by simple weight loading alone. In a starting-point injection-molding LSR, RH-Vi306 is metered into Part A at 5–30 wt% of the Part A mass, while the combined vinyl-functional polymer fraction after static mixing remains 60–85 wt% of the mixed A+B stream; Si-H:Si-Vi molar ratio is held between 1.2:1 and 1.8:1, with platinum catalyst at 2–10 ppm Pt and ethynyl cyclohexanol inhibitor at 50–200 ppm. The downstream production process uses an LSR injection machine with barrel temperature 15–25 °C, screw compression ratio 1.0:1–1.2:1, and a 6–12-element static mixer feeding a hot runner nozzle; mold temperature is kept at 120–180 °C, and cure time for a 2–5 mm wall section is 30–90 s. Field observation on multi-cavity production lines shows that entrapped air and local hydrosilylation imbalance are the two principal failure modes when back-pressure is below 5 MPa or when the static mixer element count drops below 6; moisture above 300 ppm in the filler or base polymer produces bubble defects at the surface. Industry compliance is anchored to ISO 37:2017 tensile testing, ISO 34-1:2022 tear strength, ISO 815-1:2019 compression set, and ASTM D2240-15(2021) hardness; food-contact grades are evaluated under FDA 21 CFR 177.2600, and medical components under USP Class VI or ISO 10993-5. Terminal finished product types include automotive connector seals, infant feeding nipple components, medical plunger tips, and hot-runner injection-molded gaskets used in small kitchen appliances.
Cure depth in optically clear electronic encapsulant formulations becomes process-limiting when the platinum cure front is faster than the evacuation of dissolved air, and RH-Vi306 is therefore formulated with low platinum inventory and staged thermal profiles rather than a single high-temperature ramp. The encapsulant matrix incorporates RH-Vi306 at 20–50 wt% of the total silicone base fluid to lower viscosity to 500–5,000 mPa·s at 25 °C, with silicon hydride crosslinker at 5–12 phr, platinum catalyst at 1–5 ppm, and adhesion promoter at 0.5–2 wt%; the Si-H:Si-Vi molar ratio is maintained at 1.3:1–1.7:1 to avoid post-cure outgassing. The downstream production process for potted power modules and light-emitting diode packages begins with vacuum deaeration at −0.09 MPa for 5–10 min, followed by meter-mix-dispense through a static mixer into aluminum or ceramic housings, and then cure at 80 °C for 30 min followed by 150 °C for 60 min. A process conflict arises when wall thickness exceeds 10 mm: the exothermic hydrosilylation front can exceed 150 °C internally and create density gradients that reduce optical transmission; this is controlled by staging the oven ramp and limiting catalyst concentration to the lower end of the stated range. Industry compliance standards include UL 94 V-0 or V-1 at 3.2 mm specimen thickness, ASTM D5470-17 for thermal conductivity, IEC 60068-2-14 for thermal cycling, and RoHS Directive 2011/65/EU for restricted substances; optical-grade products are additionally screened for total transmittance after thermal aging at 150 °C for 500 h. Terminal finished product types include light-emitting diode package lenses, chip-on-board encapsulation, insulated-gate bipolar transistor potting, power supply housings, and automotive lighting modules.
Table 1. Property verification matrix for LED encapsulant formulations:
| Property | Standard designation | Specimen condition or test method |
|---|---|---|
| Vertical burn | UL 94 | 3.2 mm bar, V-0 or V-1 |
| Thermal conductivity | ASTM D5470-17 | Steady-state, 25 °C mean temperature |
| Thermal cycling | IEC 60068-2-14 | -40 °C to 125 °C, 500 cycles |
| Restricted substances | RoHS Directive 2011/65/EU | Homogeneous material |
On a five-roller solventless thermal release coating line, RH-Vi306 functions as a controlled-release-strength modifier for platinum-catalyzed silicone systems applied to paper and film substrates; the coater is configured with a 0.8–1.5 g/m² coat weight target, a 120–150 °C oven temperature, and a dwell time of 10–20 s at line speeds from 300 m/min to 600 m/min depending on substrate thermal mass. The coating bath incorporates RH-Vi306 at 0.5–5 wt% of the total fluid, with platinum catalyst at 30–100 ppm and silicon hydride crosslinker at 3–8 phr; the low addition ratio is made necessary by the fact that excess vinyl silicone oil shifts liner release force below 5 cN/25 mm and creates re-adhesion failure in downstream label converting. Substrate pre-treatment by corona discharge is set to 36–42 dyn/cm surface energy, and film or paper is cooled immediately after the oven to prevent blocker marking on the rewound roll. Compliance for food-contact release liners is assessed under FDA 21 CFR 176.170 and FDA 21 CFR 176.180 migration limits, EU Regulation 10/2011 for plastic materials, and ISO 14001 for the converting line if the customer audit scope requires it. Terminal finished product types include pressure-sensitive label release liners, adhesive tape backings, medical plaster liners, and food packaging labels.
High-temperature vulcanizing silicone gum compounding with RH-Vi306 is performed on a two-roll mill or internal mixer at 1–8 phr as a reactive plasticizer to lower Mooney viscosity and improve filler wetting while retaining the 1.8:1–2.5:1 Si-H:Si-Vi ratio required for peroxide-free hydrosilylation cure; the compounded stock is press-cured at 170 °C for 10 min and post-cured at 200 °C for 4 h, with compliance to ASTM D926 Williams plasticity, ISO 37:2017 tensile strength, ISO 34-1:2022 tear strength, and FDA 21 CFR 177.2600 for food-contact articles. Terminal finished product types include extruded oven gaskets, molded kitchenware seals, silicone tubing, and reciprocating pump diaphragms.
The expansion of platinum-cured silicone foam is a kinetic competition between gas evolution and hydrosilylation network formation; when RH-Vi306 is used as the base vinyl polymer in a battery pack seal, the formulation must delay gelation until the blowing agent has produced the target cell structure. Typical addition ratios for a hydrosilylation-cured silicone foam place RH-Vi306 at 30–70 wt% of the total silicone base polymer, with methyl hydrogen silicone fluid having Si-H content 0.3–0.8 wt% added at 10–25 phr, water or ethanol blowing agent at 1–5 phr, platinum catalyst at 5–15 ppm, and inhibitor at 100–300 ppm; the Si-H:Si-Vi molar ratio is set between 1.5:1 and 2.5:1 because a portion of the hydride is consumed by water. The downstream production process uses a meter-mix-dispense system with a static mixer that feeds a cavity held at 60–80 °C for 5–10 min to nucleate and expand the foam, followed by 120–150 °C final cure for 30–60 min; expansion ratios are typically 1.5:1–4:1, and final foam density falls between 0.2 g/cm³ and 0.6 g/cm³. The critical process window is narrow: adding more than 25 phr hydride fluid or reducing inhibitor below 100 ppm causes premature gelation that traps blowing agent and produces closed-cell collapse, while hydride levels below 10 phr produce under-crosslinked foam with compression set above 20% after 70 h at 100 °C. Compliance standards for this application include UL 94 V-0 at 3.2 mm specimen thickness, UL 94 5VA for flame penetration, IEC 62619 for secondary lithium battery safety, and SAE J2464 for abuse testing; REACH (EC) No 1907/2006 applies for European Union market access. Terminal finished product types include battery module side seals, fire-resistant thermal barriers, cell compression pads, and vibration-damping gaskets in traction battery enclosures.
Medical-grade addition-cure silicone elastomers formulated with RH-Vi306 require a dual biological and chemical compliance position before any production lot is released; the cured elastomer is tested for cytotoxicity under ISO 10993-5:2009 with MEM elution at 37 °C for 24 h, for irritation and sensitization under ISO 10993-10:2010, and for systemic injection and skin irritation under USP Class VI protocols. The formulation uses RH-Vi306 at 5–20 wt% of the silicone polymer fraction to reduce Shore A hardness from approximately 30A to 5A, with vinyl-functional gum as the major polymer, silicon hydride crosslinker added to maintain an Si-H:Si-Vi molar ratio of 1.4:1–1.6:1, platinum catalyst at 2–8 ppm, and no amine-containing adhesion promoters that would compete with the platinum catalyst and create yellowing or extractable residues. The downstream production process is split between two-part liquid injection molding and cast molding; both routes require a final post-cure at 200 °C for 4 h to reduce volatile siloxanes below the customer specification of 0.5 wt%, with mixing carried out under ≤40% relative humidity to prevent moisture-induced inhibition. Compliance for skin-contact finished devices also includes FDA 21 CFR 177.2600 for repeated-use rubber articles and, where applicable, ISO 14962 for tissue engineering scaffolds or ISO 14981 for device-specific biological evaluation. Terminal finished product types include continuous positive airway pressure mask cushions, wearable electrocardiogram electrode substrates, hearing aid components, and skin-contact pad interfaces.
Competitive Vinyl Silicone Oil RH-Vi306 prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8618005193850 or mail to sales8@bouling-chem.com.
We will respond to you as soon as possible.
Tel: +8618005193850
Email: sales8@bouling-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Vinyl Silicone Oil RH-Vi306 is a vinyl-terminated polydimethylsiloxane supplied as a colourless transparent liquid. In addition-cure silicone compounding, the terminal vinyl groups participate in hydrosilylation with polymethylhydrogen siloxane crosslinkers under platinum catalysis. The grade is applied as a base polymer in liquid silicone rubber, as a reactive diluent in solventless release coatings, and as a process fluid in peroxide-cured high-temperature vulcanizing elastomer compounds. Table 1 lists the lot-release profile. The values represent the producer’s published specification envelope and are verified by the cited methods.
| Property | Standard method | Typical range or limit |
|---|---|---|
| Appearance | Visual inspection | Colourless transparent liquid |
| Kinematic viscosity at 25 °C | ISO 3104 | 900–1,100 mm²/s |
| Vinyl content | Iodometric titration | 0.30–0.36 mmol/g |
| Volatile content | ISO 3251 | ≤0.5 wt% |
| Refractive index nD25 | ISO 2807 | 1.403–1.407 |
| Specific gravity at 25 °C | ISO 2811 | 0.970–0.980 |
The terminal location of the vinyl groups confers a network architecture that differs from pendant vinyl fluids. Because the reactive functionality sits at chain ends, the polyaddition step extends linear segments between crosslink junctions. The resulting network exhibits lower modulus at equivalent total vinyl content when compared with fluids containing internal vinyl functionality. In moving-die rheometer testing under ISO 6502-3, the maximum torque is typically lower than a pendant-vinyl control at identical SiH:SiVi molar ratio; exact torque decrement is formulation-dependent. A fixed crosslinker feed intended for a pendant vinyl fluid can produce a softer and tackier article unless the hydride crosslinker addition is adjusted to an SiH:SiVi ratio of 1.3:1 to 1.8:1. Elongation at break is evaluated under ISO 37 after curing 10 min at 150 °C.
As a difunctional vinyl-terminated dimethylsiloxane, the material can be described by CAS 68083-19-2 and is produced by base-catalyzed ring-opening polymerization of octamethylcyclotetrasiloxane followed by vinyl end-capping. The terminal dimethylvinylsilyl groups are present at each polymer chain end. This structure differentiates it from fluids end-capped with trimethylsilyl groups but otherwise similar backbone chemistry.
At the mixer outlet, viscosity under low-shear conditions is near the base polymer value. Under injection shear rates of 1,000–10,000 s−1, filled compounds exhibit pseudoplastic behavior more pronounced than the Newtonian behavior of the neat fluid; filler type controls this. Neat RH-Vi306 shows minimal shear thinning below 100 s−1, which suits it for use as a reactive diluent in high-filler systems where thixotropy must be controlled.
In liquid injection molding, RH-Vi306 is metered as the Part A base polymer with a platinum catalyst. A methylhydrogen siloxane crosslinker is metered as Part B. Mixing is executed in a static mixer containing 12–24 elements at feed pressures of 5–15 MPa. The mixed compound is injected into a closed mold at 110–180 °C. The lower mold-temperature bound is set by cure kinetics: at 110 °C, the moving-die rheometer t90 may exceed 300 s, which is generally incompatible with high-cavitation molding. The upper bound is governed by inhibitor volatility and platinum catalyst deactivation. At mold temperatures above 180 °C, the common inhibitor 1-ethynyl-1-cyclohexanol volatilizes rapidly, shortening pot life and increasing the risk of scorch in the mixing block. A compound temperature rise above 200 °C can produce localized gel particles that block the static mixer and cause short shots.
Mold fouling is observed when volatile fraction exceeds 1.0 wt%. In closed-tool liquid injection molding, deposits accumulate on the parting line and ejector pins. Shore A hardness variation across a molded cushion can exceed ±2 points when mixing quality declines because of inadequate static mixer length or worn mixer elements. Production-scale trials with a 180 t horizontal injection molding machine and a cold-runner system set at 25–35 °C have demonstrated stable cycle times of 45–90 s for parts with wall thickness 2–3 mm. Published data for this specific configuration is limited, but these boundaries are consistent with platinum-catalyzed addition-cure systems.
On solventless thermal release coating lines that use five-roll offset gravure, RH-Vi306 is compounded with a methylhydrogen siloxane crosslinker and a platinum catalyst at 0.8–1.5 g/m² coat weight on glassine or kraft. Cure is carried out at 160–180 °C with dwell times of 3–8 s. Release force is evaluated at 300 mm/min peel under FINAT FTM 3, with typical values of 10–30 cN/50 mm depending on crosslinker ratio and post-cure aging. The low volatile content reduces idler roll deposit formation and allows stable coat weight over continuous runs exceeding 20,000 m. Extractable unpolymerized fluid is the operational boundary: incomplete curing due to catalyst poisoning by airborne amines or sulfur leaves a migratory film that increases subsequent adhesive adhesion loss. Lot-to-lot viscosity drift outside ±100 mm²/s produces measurable coat weight variation because transfer pickup on five-roll offset gravure is sensitive to fluid viscosity.
Vinyl content is determined by iodometric titration. The envelope of 0.30–0.36 mmol/g corresponds to a calculated number-average molecular weight of approximately 5,600–6,700 g/mol for difunctional termination. Batches near the upper vinyl limit produce higher crosslink density and lower elongation at a fixed SiH:SiVi ratio. Crosslinker addition is therefore normalized to the actual lot vinyl content rather than to total polymer mass. Kinematic viscosity is controlled to 900–1,100 mm²/s at 25 °C under ISO 3104. Density is 0.970–0.980 g/cm³ by ISO 2811. Volatile content is limited to ≤0.5 wt% when tested at 150 °C for 3 h under ISO 3251. A lot with volatile content above 1.0 wt% is not recommended for closed-tool liquid injection molding because released condensables deposit on mold surfaces and ejector pins.
At relative humidity above 60%, predrying is recommended at 120 °C under vacuum of −0.095 MPa for 1 h before platinum-catalyzed processing. Adventitious water can hydrolyze the hydride crosslinker and generate hydrogen, producing bubbles in thick sections. The material is incompatible with amine-containing additives, organotin compounds, and sulfur-containing accelerators. Platinum catalyst deactivation has been observed at concentrations as low as 10 ppm; incomplete cure appears as surface tack and low crosslink density.
Lot certificates include compliance documentation under REACH and RoHS; restricted-substance screening is reported per IEC 62321. This is applicable when the cured compound is supplied into electrical and electronic equipment assembly.
In peroxide-cured high-temperature vulcanizing silicone rubber, RH-Vi306 is added at 3–8 phr on a two-roll mill with a nip gap of 0.2–0.5 mm and roll temperature held below 40 °C. At these addition levels, compound viscosity decreases without a large increase in crosslink density because the terminal vinyl groups are less efficient in peroxide-induced radical coupling than pendant vinyl groups. At addition levels above 10 phr, bloom can occur on the cured surface, and peel adhesion to grit-blasted steel inserts, measured under ISO 813, may fall below 2 N/mm. This boundary is set by production-scale trials rather than by an intrinsic thermal stability limit.
Trimethylsilyl-terminated polydimethylsiloxane is non-reactive in the hydrosilylation network and functions as a plasticizer. It can be extracted from the cured matrix and can migrate to the surface, reducing adhesion and causing contamination in cleanroom applications. RH-Vi306 is chain-extended into the network, so extractable content after 8 h Soxhlet extraction in methyl ethyl ketone is typically lower, and compression set measured under ISO 815-1 at 150 °C for 22 h is reduced. Compared with a high-vinyl pendant fluid containing vinyl groups along the siloxane backbone, RH-Vi306 provides a more uniform network with lower localized crosslink density. At equal total vinyl concentration, this produces lower Shore A hardness, higher elongation at break, and improved tear strength under ISO 34-1. The processing consequence is that replacement of a pendant vinyl fluid with RH-Vi306 usually requires an increase in platinum catalyst concentration of 5–15 ppm to maintain equivalent cure time because terminal vinyl groups present a less sterically hindered arrangement for catalyst coordination. Published data for this specific substitution in RH-Vi306 is limited.
The lower localized crosslink density of terminal vinyl networks is reflected in dynamic mechanical analysis. The tan δ peak temperature shifts by 2–5 °C relative to pendant vinyl networks of equal total vinyl content when tested at 1 Hz under ISO 6721-1. This shift is associated with more uniform chain segment mobility rather than overall crosslink density loss. Processors may observe higher elongation before break in tensile tests and slightly lower modulus at 100% strain.
| Property | RH-Vi306 | Trimethylsilyl-terminated PDMS | High-vinyl pendant fluid |
|---|---|---|---|
| Reactive in hydrosilylation | Yes | No | Yes |
| Network function | Chain extender | Plasticizer | Crosslinker or co-crosslinker |
| Vinyl content | 0.30–0.36 mmol/g | <0.02 mmol/g | 1.0–3.0 mmol/g typical |
| Extractable tendency after cure | Low when fully vulcanized | Higher | Low when fully vulcanized |
| Hardness effect at equal vinyl content | Moderate | Reduces hardness | Increases hardness |
| Volatile tendency | Low | Low to moderate | Higher if low molecular weight |
Automotive connector seals formulated from RH-Vi306 are injection molded with 100–150 t clamping force and post-cured at 200 °C for 4 h. The low volatile content reduces pressure buildup in closed molds and limits silicone vapor deposition on electrical contacts. The cured compound is tested for compression set under ISO 815-1 at 150 °C for 22 h, with values below 20% when the crosslinker addition is normalized to the actual vinyl content. Incompatibility with tin-catalyzed condensation systems is a boundary: residual tin can poison the platinum catalyst in multi-component assembly lines.
High-voltage electronic potting compounds formulated with RH-Vi306 are processed by vacuum degassing at 25 °C and −0.095 MPa for 10–20 min before casting. The fluid’s low volatile content reduces bubble entrapment during cure, and the terminal vinyl groups allow the compound to reach Shore A 15–25 hardness with 100–200% elongation at break after 30 min at 150 °C. Pot life is controlled by inhibitor addition at 0.01–0.05 wt%; above 0.08 wt%, cure is excessively delayed under 120 °C cure schedules. The operational limit for filled systems appears when the filler content exceeds 30 wt%, at which point viscosity rises above 100,000 mPa·s and vacuum degassing times extend beyond 60 min.
Dedicated to excellence in chemistry — serving industries worldwide with integrity and innovation.
