COOLTHERM UR388
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- 0.7 W/(m K) Thermal Encapsulation
- 6,000 cP Mixed Viscosity
- 0.32% TML and 0.02% CVCM
Product Description
CoolTherm® UR-388 FST Flame Retardant Urethane Encapsulant is a two-component urethane system for encapsulating and casting applications. It cures at room temperature to form a flame-retardant, semi-flexible material with typical thermal conductivity of 0.7 W/m·K and an operating-temperature range of -55°C to +130°C. The mixed system has a typical viscosity of 6,000 cP at 25°C and combines low cure exotherm with documented thermal-shock resistance and low-outgassing performance in high-vacuum test conditions. :contentReference[oaicite:0]{index=0}
Key features
- Thermally conductive encapsulation: Provides typical cured thermal conductivity of 0.7 W/m·K.
- Low-outgassing performance: Records 0.32% total mass loss and 0.02% collected volatile condensable materials under ASTM E595-77.
- Room-temperature cure: Initially cures in less than 30 minutes at 25°C and may be mildly heat-cured at 60°C to accelerate cure.
Applications / Suitable for
- Encapsulating applications
- Casting applications
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Mechanical Properties
Electrical Properties
Additional Information
As-supplied / before-processing properties
Typical properties of CoolTherm UR-388 FST resin, UR-388 hardener and the mixed encapsulant before cure. Values are not intended for specification purposes. :contentReference[oaicite:1]{index=1}
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Black liquid / Amber liquid / Black liquid | — | UR-388 FST resin / UR-388 hardener / mixed system |
| Viscosity | 15,000 / 70 / 6,000 | cP | Resin / hardener / mixed system at 25°C; test method not stated |
| Specific gravity | 1.53 / 1.24 / 1.50 | — | Resin / hardener / mixed system; test conditions not stated |
| Mix ratio | 100:20 / 100:24 | Resin:hardener | By weight / by volume |
| Gel time | 5 | minutes | Mixed system at 25°C; test method not stated |
| Suggested cure schedule | 24 hours to 7 days | — | At 25°C; initial cure occurs in less than 30 minutes |
| Shelf life | 6 | months | Each component from date of manufacture when stored at 25°C in the original, unopened container |
After-processing / final-state properties
Typical cured properties of CoolTherm UR-388 FST. The source does not identify the cure schedule used to prepare the cured-property specimens. Values are not intended for specification purposes. :contentReference[oaicite:2]{index=2}
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Thermal conductivity | 0.7 | W/m·K | Test method, temperature and specimen thickness not stated |
| Operating-temperature range | -55 to +130 | °C | Documented range for parts and devices; retained-property data are not stated |
| Hardness | 88 | Shore A | ASTM D2240 |
| Tensile strength | 15.58 (2,260) | MPa (psi) | ASTM D638 |
| Elongation at break | 50 | % | ASTM D638 |
| Volume resistivity | 7 × 1015 | ohm-cm | At 25°C; ASTM D257 |
| Dielectric constant | 6.2 | — | At 25°C and 1 MHz; ASTM D150 |
| Dissipation factor | 0.013 | — | At 25°C and 1 MHz; ASTM D150 |
| Total mass loss | 0.32 | % | ASTM E595-77 |
| Collected volatile condensable materials | 0.02 | % | ASTM E595-77 |
