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BLUESIL ESA 7252 B
Crosslinker (component B) for the addition-crosslinking RTV-2 system BLUESIL ESA 7252 (mixing ratio 1:1): Potting and encapsulation of electrical components, connectors and sensors with thermal protection and fire protection (aviation).
BLUESIL ESA 7252 B is the B component (white) of the addition-curing, two-component silicone elastomer ESA 7252, which cures at room temperature; heating accelerates the curing process. The system is used for potting and encapsulating electrical components, connectors, and sensors in onboard electronics, as well as for thermal and fire protection in the aerospace industry. It offers outstanding flame resistance, good thermal conductivity, low viscosity, rapid curing, and is non-corrosive. It is processed in conjunction with BLUESIL ESA 7252 A.
Documents
Internal reference:
40-7252B
HS code:
39100000
Bluesil ESA 7252 A & B is a 2K-Pt silicone with excellent flame resistance (UL 94 V0) and good thermal conductivity (0.42 W/m·K) for thermal and fire protection in aerospace potting.
This product line comprises 2K polyaddition silicone elastomers with exceptional flame resistance (UL 94 V0) and thermal conductivity for aerospace and fire protection applications. ESA 7252 is tailored to specific industrial applications—the key properties and areas of application are listed below.
Bluesil ESA 7252 is the fire-resistant specialist choice of the ESA series — excellent flame resistance (UL 94 V0) and good thermal conductivity (0.42 W/m·K). Ideal for encapsulation in aviation, junction boxes, and applications requiring thermal heat dissipation.
What distinguishes ESA 7252
What is ESA 7252 used for?
Processing
Recommended accessories
Important Notes
ESA 7252 compared to related RTV products
Crosslinking system, mechanics, and processing times directly side by side — all values from the official Elkem-TDS. “— " = not specified in the data sheet.
ESA 7252 Current Product |
RTV 8352 LV → | ESA 7250 → | V-695 → | |
|---|---|---|---|---|
| Crosslinking system | 2K Polyaddition (Pt) | 2K Polyaddition (Pt) | 2K Polyaddition (Pt) | 2K Polyaddition (Pt) |
| Mixing ratio | 1 : 1 | 1 : 1 | 10 : 1 | see TDS |
| Color | Black (A) / white (B) | Whitish | Optically clear, colorless | Black |
| Shore A hardness | A 48 | A 55 | A 52 | see TDS |
| Elongation at break | 170 % | 78 % | 115 % | — |
| Tensile Strength | 2.3 MPa | 2.3 MPa | 6.2 MPa | — |
| Tear strength | — | — | 4 kN/m | — |
| Pot life | 1.5 h | 130 min | 4 h | long |
| Demolding time | 8 h (RT) / 5 min @ 150 °C | 8 h | 24–48 h | with heat treatment |
| Mixed viscosity | 3,000–3,500 mPa·s | 2'200 mPa·s | 4'000 mPa·s | flowable |
| Main application | Aerospace fire protection | Electrical Engineering Encapsulation | Electronics potting | Jet engine compressor air seals |
Technical data for BLUESIL ESA 7252 B
| Product Information | |
|---|---|
| Brand | Bluesil |
| Manufacturer | Elkem Silicones |
| Mixing Ratio | 1:1 |
| Curing type | Addition (Platinum) |
| Number of components | 2K (two-component) |
| Consistency | Flowable |
| Mixing Ratio | 1:1 |
| Container | 1 kg, 5 kg, 25 kg |
| Further Properties | |
|---|---|
| UV resistance | Yes |
| Physical Properties | |
|---|---|
| Cured Color | Transparent |
| Self-leveling | Yes |
| Uncrosslinked viscosity (mPa·s) | 3500 |
| Electrical Properties | |
|---|---|
| Electrical Insulation | Yes |
| Product Approvals | |
|---|---|
| Food contact | No |
| Medical grade | No |
| Mechanical properties | |
|---|---|
| Tensile strength (MPa) | 2.3 |
| Elongation at break (%) | 170 |
Please refer to the technical data sheet (TDS) in the "Documents" tab for binding values.
Documents and data sheets
Click on a document for the preview or the download icon for direct download.
Frequently asked questions about ESA 7252
Practical processing and design questions — answered by SILITECH.
Bluesil ESA 7252 A & B: 2-component platinum silicone with excellent flame resistance (UL 94 V0) and good thermal conductivity (0.42 W/m·K) for thermal and fire protection in aerospace potting. Main applications include aerospace fire protection, power electronics with heat dissipation, and connection boxes.
Polyaddition crosslinking is a 2-component silicone chemistry with a platinum catalyst. Component A contains the platinum complex, component B the SiH crosslinker. When mixed, the components crosslink without releasing reaction by-products — no shrinkage due to outgassing substances, excellent dimensional accuracy, low linear shrinkage. Important: Polyaddition silicones are inhibited by various substances — sulfur-vulcanized natural rubbers, tin-catalyzed RTV silicones, amine-catalyzed epoxy resins, PVC stabilized with tin salts. In case of doubt, a preliminary test must be carried out.
Thoroughly stir components A and B before each processing step. Dose precisely according to the mixing ratio specified in the TDS (see comparison table above) — preferably by weight. Mix with an electric or pneumatic stirrer at low speed (minimize air entrainment). Degas the mixture under vacuum (30–50 mbar) — the material expands to 3–4 times its volume, bubbles escape, and the material settles back after 5–10 minutes. Then pour slowly into the mold from the lowest point to avoid air entrapment. For polyaddition systems, avoid contact with inhibitors (sulfur rubber, tin RTV, amine epoxides, PVC with tin salts).
Store in unopened original container in a dry, cool place — typically between +5 and +30 °C, exact values see TDS. Store components A and B separately; after opening, seal airtight. Polyaddition systems are insensitive to moisture, but should be stored cool to preserve pot life. Consult the Safety Data Sheet (SDS) before use.
In the comparison table above, you will find related RTV products with different hardnesses, pot lives, or application profiles. If you are unsure about the optimal choice, we will be happy to advise you — contact SILITECH with your application (substrate, desired hardness, processing time, requirements for mechanical properties and resistance).
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Product Specifications
| Product Information | |
|---|---|
| Container | 1 kg or 5 kg or 25 kg |
| Brand | Bluesil |
| Manufacturer | Elkem Silicones |
| Mixing Ratio | 1:1 |
| Curing type | Addition (Platinum) |
| Number of components | 2K (two-component) |
| Consistency | Flowable |
| Mixing Ratio | 1:1 |
| Further Properties | |
|---|---|
| UV resistance | Yes |
| Physical Properties | |
|---|---|
| Cured Color | Transparent |
| Self-leveling | Yes |
| Uncrosslinked viscosity (mPa·s) | 3500 |
| Electrical Properties | |
|---|---|
| Electrical Insulation | Yes |
| Product Approvals | |
|---|---|
| Food contact | No |
| Medical grade | No |
| Mechanical properties | |
|---|---|
| Tensile strength (MPa) | 2.3 |
| Elongation at break (%) | 170 |
| Keywords | |
|---|---|
| Keywords | |
| Processing | |
|---|---|
| Viscosity of Mixture | 1’200 mPa·s |
| Viscosity Comp. A | 1’000 mPa·s |
| Viscosity Component B | 1’200 mPa·s |
| Pot life at 23°C | 40.0 min |
| Physical & Thermal | |
|---|---|
| Density (23°C) | 0.98 g/cm³ |
| Temperature Resistance (Continuous) | -50 to 200 °C |
| Peak Temperature (Short-term) | 200 °C |
| Electrical characteristics | |
|---|---|
| Dielectric constant ε (1 kHz) | 2.8 |
| Dielectric strength | 23.0 kV/mm |
| Volume resistivity | 1e+15 Ω·cm |
| Dissipation factor tan δ | 0.001 |
| Storage | |
|---|---|
| Shelf life in original packaging | 12 months |
| Storage Temperature | -10 to 30 °C |
Documents and data sheets
Safety Data Sheets (SDS) and Technical Data Sheets (TDS) for download: