| HS Code | 309313 |
| Chemical Type | Vinyl-terminated polydimethylsiloxane |
| Appearance | Colorless transparent liquid |
| Viscosity At 25 C | Approximately 300 mPa·s |
| Vinyl Content | Approximately 0.2–0.3 wt% |
| Density At 25 C | Approximately 0.97 g/cm³ |
| Refractive Index At 25 C | Approximately 1.404–1.406 |
| Volatile Content | Typically ≤1.0 wt% |
| Flash Point | Typically >100°C |
| Surface Tension | Approximately 21–22 mN/m |
| Dielectric Constant At 25 C And 1 Khz | Approximately 2.7–2.8 |
| Dielectric Strength | Typically ≥15 kV/mm |
| Dissipation Factor At 25 C And 1 Khz | Typically ≤0.001 |
As an accredited Vinyl Terminated Silicone Oil RH-Vi302 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | RH-Vi302 Vinyl Terminated Silicone Oil is packaged in sealed 25 kg plastic drums, with 200 kg drums available for bulk supply. |
| Container Loading (20′ FCL) | Vinyl Terminated Silicone Oil RH-Vi302 securely loaded in a 20-foot FCL container, packed in drums for export shipment. |
| Shipping | RH-Vi302 is shipped as a non-hazardous silicone oil, not regulated for transport under DOT/IATA/IMDG/ADR. Use sealed, labeled drums or IBCs; protect from moisture, contamination, and extreme temperatures. Store in a cool, dry, ventilated area. Ensure containers are closed and secured during transit. Handle per SDS and local regulations. |
| Storage | Store in the original container in a cool, dry, well-ventilated place, away from direct sunlight, heat, and ignition sources. Keep containers tightly closed to prevent contamination by moisture, dust, or other materials. Avoid contact with strong oxidizers, acids, and alkalis. Use secondary containment and follow local regulations. Do not freeze; avoid excessive heat. |
| Shelf Life | Shelf life is typically 12 months from manufacture when stored in the original, unopened container under recommended conditions. |
Metering and mixing of addition-cure liquid silicone rubber based on vinyl-terminated polydimethylsiloxane such as RH-Vi302 begins with a 1:1 A/B static mixing sequence in which Part A carries a platinum–divinyltetramethyldisiloxane complex and Part B carries polymethylhydrogen-co-dimethylsiloxane with an alkyne inhibitor. The reactive window is established from the terminal vinyl concentration reported on the certificate of analysis; when the COA reports a Si-Vi content of 0.10–0.30 mmol/g, the formulation is adjusted to maintain a molar ratio of Si-H to Si-Vi from 1.2:1 to 1.8:1. At a ratio below 1.1:1 the network remains undercrosslinked: moulded plaques cured at 150°C for 10 min show a Shore A hardness reduction of 3–5 points and compression set tested by ASTM D395 Method B at 150°C for 22 h rises above 35%. At a ratio above 2.2:1, residual Si-H functions cause post-cure hardness drift, hydrogen evolution in alkaline environments, and surface tack on adjacent EPDM sealing elements. Injection moulding lines with 50–200 t clamp force and water-cooled barrels held at 20–40°C process the mixed compound through a 15–20-element static mixer; the mould is held at 125–175°C and cure time is 0.8–1.5 s per millimetre of wall section. Gate thickness is fixed at 0.3–0.8 mm for thin-wall seals because smaller gates generate premature shear heating and scorch in the runner system. Typical vulcanizate properties after post-cure fall between 6–10 MPa tensile strength with 350–650% elongation at break when tested according to ASTM D412, while tear resistance by ASTM D624 Die B is 20–40 N/mm. Finished components include infant feeding teats, respiratory mask cushions, automotive gaskets, and pharmaceutical pump diaphragms. Compliance for food-contact and medical uses is routinely assessed under FDA 21 CFR 177.2600, ISO 10993-5, and USP Class VI when the formulation, filler pre-treatment, and platinum loading are batch-controlled. Platinum poisoning by sulfur compounds in nitrile gloves, amine-based mould release residues, or organotin contaminants must be excluded from the mixing zone. Fillers should be pre-dried at 120°C for 2 h when ambient relative humidity exceeds 60%; otherwise silanol moisture promotes premature gelation and reduces the mixed compound pot life below the 24–48 h normally expected at 25°C.
Vacuum potting of power-LED modules imposes stricter requirements on gas void content, thermal ageing, and optical clarity than moulded sealing compounds. When RH-Vi302 is used as the base vinyl fluid in a two-part optical encapsulant, the Si-H:Si-Vi ratio is held between 0.9:1 and 1.3:1 rather than the higher ratios common in rubber moulding, because surplus silicon hydride reacts with atmospheric moisture to generate silanol species that later condense into haze-causing domains or produce hydrogen bubbles during humidity ageing. The mixed viscosity at 25°C is typically 1200–3500 mPa·s, and the refractive index of the cured PDMS phase remains near 1.41; light transmittance through a 2 mm cured sheet is specified above 90% with haze below 1.0% by ASTM D1003. Component substrates are pre-dried at 60–80°C for 2–4 h before potting because residual water vapor accelerates platinum catalytic inhibition and increases optical attenuation at the bond line. Degassing is performed at 5–10 mbar for 10–15 min in a planetary centrifugal mixer, followed by room-temperature idle until the bubble surface is clear; the mixed material is then dispensed into COB LED cavities by a positive-displacement jet valve with a needle temperature of 25–35°C to prevent viscosity drift. Curing is staged: 80°C for 1 h followed by 160°C for 2 h under nitrogen or forced air with oxygen content below 2%, because high air exposure during the final ramp oxidises residual Si-H and shifts Shore A hardness upward by 3–8 points. Hardness after cure is typically Shore A 25–45 by ASTM D2240. The terminal vinyl fluid contributes lower crosslink density than branched vinyl resins, which is desirable for thermal stress relief on silver-plated leadframes; however, it also increases softness and oil-bleed tendency in high-temperature LED lighting modules. Finish applications include COB LED encapsulation, optical sensor potting, and fibre optic coupler potting. Batch-specific verification is required because published data for this specific configuration is limited; optical transmittance, yellowing index by ASTM D1925, and UL 746E thermal endurance are generally confirmed on the final cured formulation.
In high-consistency rubber compounding, RH-Vi302 functions as a reactive diluent added to a 45–60 Mooney ML 1+4 high-molecular-weight silicone gum to lower viscosity before extrusion, calendering, or transfer moulding without becoming a non-reactive extractable. The addition level is 2–10 phr; at 5 phr the Mooney viscosity falls by approximately 20–30 units and the compound shore hardness after cure is reduced by 2–4 Shore A points, enabling extrusion of 8–12 mm diameter uncured profiles with die swell below 15%. This is operationally important for pharmaceutical closures and food-contact gaskets where high tear resistance must be retained after steam sterilisation at 121°C for 30 min. The silica-filled compound is prepared on a two-roll mill or in an internal mixer with roll temperatures held below 40°C; the vinyl-terminated fluid is added only after the fumed silica has been fully wet into the gum, otherwise the fluid lubricates the pigment-filler interface and delays filler incorporation. Curing is performed in a vacuum compression press at 165–175°C for 8–12 min, followed by a forced-air post-cure of 200°C for 4 h. Omission of post-cure leaves volatile oligomer content above 0.5% and can increase extractables beyond the limits expected for rubber articles under FDA 21 CFR 177.2600. Typical mechanical values after post-cure include ISO 37 tensile strength above 8 MPa, elongation at break above 400%, and ISO 815 compression set below 15% after 22 h at 150°C. If the fluid is added above 15 phr, elongation recovery after compression moulding falls below 300%, the vulcanizate softens under heat, and the crosslink density is insufficient for high-pressure sealing elements. Finished components include respiratory valve gaskets, automotive intercooler seals, wire connector seals, and dairy pipeline gaskets. On production lines, batch-to-batch variance in the vinyl fluid viscosity of ±10% must be compensated by mill speed and nip gap adjustments to prevent stock splitting and inconsistent extrudate density.
Substituting RH-Vi302 for a non-reactive dimethyl silicone fluid in a thermal-cure release coating bath converts a migratory lubricant into a network-bound component, thereby lowering the re-adhesion loss of pressure-sensitive adhesive laminates during ageing. The coating fluid is blended with a trimethylsilyl-terminated polymethylhydrogen-co-dimethylsiloxane having a Si-H content of 10–30 mol% and a platinum–vinylsiloxane catalyst at 50–120 ppm Pt. The bath is inhibited with 0.02–0.06 phr of 2-methyl-3-butyn-2-ol to maintain 24 h pot life at 25°C; at 35°C pot life drops below 8 h and the mixture should be cooled by a chilled coating pan. Application is made by five-roll offset gravure or multi-roll direct gravure at a coat weight of 0.8–1.5 g/m² on corona-treated biaxially oriented polypropylene film or glassine. The oven is zoned: 130°C for 8 s followed by 150°C for 10–15 s; line speed is generally 200–500 m/min. Release force measured by FINAT FTM 3 at 300 mm/min should fall between 5 and 30 cN/25 mm; subsequent adhesion by FINAT FTM 4 should remain above 85% of the uncoated control. If line speed exceeds 500 m/min at the same oven dwell, residual Si-H produces a release-force drift of more than 10 cN/25 mm after 7-day ageing at 50°C. End uses are pressure-sensitive label liners, graphic film liners, PSA tape release liners, and medical dressing release papers. Compliance is routinely assessed under FDA 21 CFR 175.320 and BfR Recommendation XV; food-contact migration testing uses n-hexane extractives and the final cured layer must be free of post-cure liquid-like oligomer coverage.
| Release coating parameter | Low boundary | High boundary | Measurement method |
|---|---|---|---|
| Coat weight (g/m²) | 0.8 | 1.5 | Gravimetric |
| Cure temperature (°C) | 130 | 150 | Oven thermocouple |
| Release force (cN/25 mm) | 5 | 30 | FINAT FTM 3 |
| Subsequent adhesion (%) | >85 | >92 | FINAT FTM 4 |
| Platinum catalyst (ppm) | 50 | 120 | Inductively coupled plasma |
Because closed-cell silicone foam produced by addition cure develops its cell structure at a narrow processing window, RH-Vi302 is compounded with MQ resin and a polyhydrogenmethylsiloxane crosslinker at Si-H:Si-Vi ratios of 2.0:1 to 4.0:1 to preserve expansion while allowing skin formation at the mould wall. Blowing is achieved with 1–5 wt% expandable microspheres having an onset temperature of 80–100°C and a maximum expansion temperature of 130–150°C. The compound is meter-mix injected into a vented aluminium tool held at 120°C; cure time is 5–10 min. At mould temperatures below 110°C, expansion exceeds the cure front, causing cell collapse and a density below 0.25 g/cm³ with visible surface voids. Above 140°C, the crosslinking film forms before full expansion, producing internal blowholes and a compression set above 30% after 50% compression for 22 h at 70°C. Density is controlled from 0.25 to 0.55 g/cm³ by adjusting microsphere loading and injection shot weight. ASTM D1056 grade 2C2 and 2D3 are specified for closed-cell silicone sponge; compression force deflection at 25% deflection is 20–60 kPa. Finished parts include electric vehicle battery cell separators, rail transit door seals, and HVAC duct gaskets. Flame performance is verified by UL 94 V-0 when a platinum content of 5–15 ppm is maintained; platinum below 5 ppm fails the afterflame time limit of 10 s and causes inconsistent cell wall crosslinking in the enclosed oven zone.
Potting of insulated-gate bipolar transistor modules and automotive sensor housings uses a two-part addition-cure silicone gel in which the vinyl-terminated fluid functions as both crosslinkable chain extender and viscosity reducer. The Part A/Part B ratio is 1:1 by volume; cured gels exhibit Shore 000 hardness of 30–60 when tested by ASTM D2240, mixed viscosity of 800–1500 mPa·s at 25°C, and dielectric strength above 12 kV/mm by IEC 60243-1. The Si-H:Si-Vi ratio is held at 0.8:1 to 1.1:1 to avoid hardness drift and oil bleed. Degassing is performed at 5–10 mbar for 10–15 min before vacuum potting into modules; entrapped air in copper leadframe corners reduces dielectric strength by 20–30%. Curing can be 100°C for 15 min or 23°C for 24 h; the slower room-temperature schedule reduces shrinkage in large modules to below 0.1% and prevents detachment from silicone-coated copper wires. Incompatible surfaces include raw brass, zinc-plated terminals, and amine-epoxy mould flash, which can inhibit the platinum complex and leave a liquid layer at the interface. End uses are ECU modules, power steering sensors, and high-voltage battery management system boards. Compliance includes UL 94 V-0 at 2 mm thickness and RTI 150°C; published data for RH-Vi302-specific gel formulations is limited, so batch-specific IEC 60243-1 and ISO 10993-5 data are required for medical or high-voltage certification.
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Vinyl Terminated Silicone Oil RH-Vi302 is a linear divinyl-terminated polydimethylsiloxane fluid identified by the CAS registry number 68083-19-2. The polymer carries one reactive vinyl group at each terminal silicon atom, giving a telechelic architecture that participates in platinum-catalyzed hydrosilylation rather than moisture-driven condensation. A representative lot exhibits a dynamic viscosity of 3000 mPa·s at 25 °C under ISO 3219:2021, a density of 0.975 g/cm³ at 25 °C under ISO 2811-1:2016, and a refractive index of 1.4040 at 25 °C. The specification window for production lots is not a single point; batch-to-batch variation is controlled within a defined band because elastomer hardness and release force respond to stoichiometric deviations.
Because the vinyl groups are exclusively terminal, the fluid yields defined network architectures in addition-cure silicone elastomers, gels, and release coatings. This molecular feature differentiates RH-Vi302 from dimethylsilicone fluids with pendant vinyl groups, which produce steeper crosslink density gradients at the same silicon-bonded vinyl concentration. In contrast to methyl-terminated polydimethylsiloxane, which is non-reactive, RH-Vi302 acts as a crosslinkable base polymer or reactive diluent, provided that residual moisture and catalyst poisons are controlled. The absence of terminal hydroxyl groups removes the silanol condensation pathway, so cure does not generate water or require atmospheric humidity.
The following table lists representative quality-control ranges. The batch-specific certificate of analysis should be requested before setting the Si–H:Si–vinyl ratio in high-precision addition-cure systems, because the reactive group concentration is the critical controlling variable rather than viscosity alone.
| Property | Test method | Representative range or value |
|---|---|---|
| Appearance | Visual inspection | Colorless transparent fluid |
| Dynamic viscosity at 25 °C | ISO 3219:2021 | 2500–3500 mPa·s |
| Density at 25 °C | ISO 2811-1:2016 | 0.970–0.980 g/cm³ |
| Refractive index at 25 °C | ISO 2807:2009 | 1.4030–1.4060 |
| Vinyl content | Iodometric titration with ¹H NMR cross-check | 0.12–0.18 mmol/g |
| Volatile content | Forced-air oven, 150 °C, 3 h | <1.0 wt% |
| Water content | ISO 760:1978 Karl Fischer titration | <200 mg/kg |
Addition-cure formulation with RH-Vi302 typically begins by blending the fluid with a poly(methylhydrosiloxane) crosslinker at an Si–H:Si–vinyl molar ratio between 1.2:1 and 1.5:1. A platinum complex catalyst is dosed to a platinum metal concentration of 5 ppm to 20 ppm. On a planetary mixer equipped with a vacuum hood, homogenization at 25 °C and 50 rpm for 30 min yields a bubble-free liquid, whereas high-shear dispersion with fumed silica may require a three-roll mill gap setting of 25 µm to 40 µm to avoid aggregate persistence. The compound remains fluid at 25 °C until thermal activation; typical cure profiles span 80 °C to 150 °C, with the gel point observed earlier at higher Si–H:Si–vinyl ratios.
When RH-Vi302 is diluted with a non-functional silicone oil, stoichiometric control becomes more sensitive. At a vinyl concentration of 0.10 mmol/g in the compounded liquid, an error of 0.01 mmol/g in the crosslinker feed can shift the final Shore A hardness by approximately 5 points. This sensitivity is why precision gravimetric or mass-flow metering is used instead of volumetric approximation in continuous coating plants. Production equipment should be fitted with temperature-controlled static mixers to prevent viscosity gradients between the A and B components.
Volatile loss and cyclic siloxane migration from cured silicones depend on the concentration of low-molecular-weight linear and cyclic species. Production lots of RH-Vi302 are devolatilized by vacuum stripping at 180 °C and 0.1 mbar for 2 h, after which headspace gas chromatography indicates that octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane together account for less than 0.1 area% of the volatile profile. This low cyclic content is relevant in optical encapsulants and release coatings where fogging on adjacent surfaces must be minimized. Thermo-oxidative exposure at 200 °C for 72 h in air can increase viscosity by ±5%; the preferred storage and processing atmosphere is dry nitrogen with a dew point below −40 °C for critical formulations.
The terminal vinyl group remains intact below 250 °C under inert conditions. Above 300 °C, thermal degradation of the siloxane backbone produces cyclic oligomers and can consume vinyl groups through radical reactions. The thermal degradation threshold is lower in the presence of residual platinum catalyst, so addition-cure compounds should not be held at 120 °C for more than 1 h before molding unless a chemical inhibitor is present.
In solventless release coatings for pressure-sensitive adhesives, RH-Vi302 is combined with a Si–H-functional crosslinker and a platinum inhibitor to extend pot life. A roll-to-roll coating head set to a wet film thickness of 1.0 µm to 2.0 µm deposits the fluid onto corona-treated polypropylene film; cure in a forced-air oven at 135 °C for 20 s is sufficient for complete conversion. The low volatile fraction of <1.0 wt% limits silicone transfer to the adhesive surface. The absence of terminal hydroxyl groups eliminates the condensation byproduct water that would otherwise destabilize moisture-sensitive adhesive formulations. Release force measured with ASTM D3330 peel adhesion on a stainless steel panel typically shifts from 5 N/25 mm to 40 N/25 mm when the crosslinker ratio is varied from 1.0:1 to 2.0:1, providing a direct method for adjusting release level without changing the base polymer.
Compounding with fumed silica at loadings above 20 wt% increases viscosity and creates a yield stress that can hide off-ratio metering faults in early production trials. For RH-Vi302, the narrow vinyl distribution obtained from terminal substitution means that the molecular weight between crosslinks is relatively uniform; however, fumed silica surface silanols can adsorb platinum catalyst and lower the effective cure rate. In a 25 mm twin-screw compounding line with L/D 48, barrel temperatures of 25 °C to 60 °C, and screw speed 300 rpm, silica dispersion reaches a Hegman grind of 6 to 7 measured by ISO 1524:2013 after a single pass. If the dispersion is stopped before a Hegman value of 6, light scattering in transparent parts increases and tensile strength measured by ISO 37:2017 may fall by 15% to 20%.
In solventborne addition-cure formulations, the solvent should have a purity grade with low inhibitor content. Toluene and xylene are generally compatible; ketones such as methyl isobutyl ketone can coordinate with platinum and slow cure. The fluid itself is soluble in most aromatic and aliphatic hydrocarbon solvents but has limited solubility in ethylene glycol and water. For pot life extension, 1-ethynylcyclohexanol is added at 0.01 wt% to 0.05 wt%; the inhibitor concentration is adjusted based on differential scanning calorimetry onset temperature.
Substitution of hydroxy-terminated polydimethylsiloxane with RH-Vi302 is not valid without formulation redesign because the condensation cure mechanism is absent. Tin carboxylate or titanate catalysts used in room-temperature vulcanizing sealants do not crosslink vinyl termini. In mixed systems, residual hydroxyl-terminated fluid domains can continue condensation while addition-cure domains crosslink, creating phase-separated networks with reduced tensile strength. For a Shore A 40 addition-cure elastomer, tensile strength measured according to ISO 37:2017 is typically 5 MPa to 8 MPa, and elongation at break is 250% to 450%, whereas a formulation containing residual hydroxy-terminated fluid may show tensile strength below 4 MPa because of network inhomogeneity.
Compared with methyl-terminated polydimethylsiloxane, RH-Vi302 has a different service profile. The non-reactive methyl-terminated fluid can be used as a heat-transfer fluid or plasticizer without catalyst sensitivity, whereas RH-Vi302 must be segregated from platinum and Si–H sources unless cure is intended. The reactive fluid also cannot be recovered by the same distillation methods after contamination because terminal vinyl groups can oligomerize at elevated temperature.
| Parameter | RH-Vi302 | Methyl-terminated PDMS | Hydroxy-terminated PDMS | Pendant vinyl PDMS |
|---|---|---|---|---|
| Reactive terminal group | Vinyl | None | Hydroxyl | Typically methyl, with pendant vinyl |
| Cure mechanism | Addition cure, platinum catalyst | No crosslinking | Condensation cure, alkoxysilane or acetate | Addition cure, platinum catalyst |
| Crosslink network architecture | Two terminal reaction sites per chain | Not applicable | Two terminal reaction sites per chain | Variable pendant reactive sites |
| Cure byproduct | None | None | Water or alcohol depending on end group | None |
| Viscosity stability in non-reactive systems | Stable if platinum and Si–H are absent | Stable | Can condense on heating or with catalyst | Stable if inhibitor present |
Pendant vinyl fluids produce a broader molecular weight between crosslinks than terminal vinyl fluids, and are therefore used as reinforcing additives or as hard segment modifiers. RH-Vi302 is selected when a defined linear chain extension with narrower gelation behavior is required. In a plate-plate rheometer cure test at 120 °C, the crossover point of storage modulus and loss modulus occurs earlier for RH-Vi302 than for a pendant vinyl fluid of the same bulk viscosity, reflecting the more uniform network formation.
Analytical cross-checks for terminal vinyl concentration use 29Si NMR; the vinyl-substituted terminal silicon appears near −4 ppm to −6 ppm relative to tetramethylsilane, while the dimethyl chain silicon atoms appear near −22 ppm. Integration of the terminal signal against the chain signal provides a direct molar mass estimate that correlates with the batch titration value. This dual method reduces the risk of mislabeled viscosity grades or unintended terminal substitution.
Platinum-catalyzed hydrosilylation is inhibited by amines, organosulfur compounds, and tin salts. Contact with amine-containing epoxy hardeners at concentrations above 10 ppm can extend gel time or arrest cure. The fluid should not be compounded in equipment that has previously processed sulfur-vulcanized rubber without thorough purging, because sulfur residues poison the platinum catalyst. Residual moisture above 60% RH during open storage can reduce Si–H consumption through competing silanol formation; therefore closed containers are required in humid production areas. Storage in high-density polyethylene drums at 5 °C to 30 °C preserves lot consistency for 12 months from the date of manufacture. At temperatures below 5 °C, viscosity increases and can be reversed by conditioning at 25 °C for 24 h.
If amino silane coupling agents are necessary for substrate bonding, incompatibility is also observed. The amino silane should be added last, and the mixed adhesive should be evaluated by differential scanning calorimetry under ISO 11357-1:2023 for a reduction in cure enthalpy. Avoid copper and palladium residues in transfer lines because these metals can perturb platinum-catalyzed cure through competitive complexation or redox activity.
In liquid silicone rubber injection molding, a two-component formulation containing RH-Vi302, fumed silica, and a Si–H crosslinker is metered through a static mixer at a 1:1 ratio. Barrel cooling at 20 °C to 30 °C prevents premature cure, while mold heating at 160 °C to 190 °C cures parts within 45 s to 120 s depending on wall thickness. The terminal vinyl architecture produces linear chain extension, while pendant vinyl contributions from the crosslinker create trifunctional network points. This distinction matters for electronic encapsulation, where low modulus and high optical clarity after thermal cycling are required. Injection molding machine clamp force for soft silicone parts typically ranges from 500 kN to 4000 kN, and molds are vented at 25 µm to 50 µm to allow air escape during flashless molding.
A rotary lobe pump with a flow rate of 20 L/h to 200 L/h and a suction-side pressure above −0.5 bar avoids cavitation when delivering RH-Vi302 at 25 °C. In-line Coriolis flow meters provide mass flow accuracy of ±0.1%, which is the preferred range for high-shear coating applications because viscosity changes alone do not track reactive group concentration. If viscous heating exceeds 10 °C through a gear pump, the viscosity can drop by approximately 10%, but the molar concentration of vinyl groups remains unchanged; therefore, thermal mass flow compensation is less reliable than Coriolis or gravimetric metering.
In high-voltage insulation and optical potting, RH-Vi302 is often mixed with fumed silica and a methylhydrogen crosslinker to achieve a cured Shore A hardness below 20, a refractive index near 1.40, and a dielectric breakdown strength above 15 kV/mm after degassing at 0.1 mbar for 10 min. The terminal vinyl fluid gives lower crosslink density than a comparable pendant vinyl silicone fluid, which is favorable for encapsulation of delicate wire bonds. Published comparative data for this specific configuration is limited; the values stated are class-typical for addition-cure PDMS gels and should be confirmed with batch-specific characterization.
Regulatory compliance of the cured silicone article depends on the complete formulation. RH-Vi302 is not classified as hazardous for transport under UN model regulations; however, uncured compounds containing platinum catalyst and hydrogen-functional crosslinker may require separate evaluation under REACH and local workplace exposure limits. Where food-contact use is intended, the finished article should be tested under FDA 21 CFR 175.300 or the applicable national legislation because residual cyclic siloxanes and platinum catalyst levels are governed by end-use migration limits, not by the bulk fluid specification alone.
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