EPOXYLITE E8121
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- Thin-Bond-Line Adhesive Cementing
- Extended Thin-Bond-Line Work Time
- High-Temperature Lap Shear
Product Description
EPOXYLITE E8121 Hi Temp Epoxy Adhesive is a two-component heat-cured adhesive supplied as a viscous liquid resin and powder hardener in premeasured kits. It is used for cementing applications that require high thermal resistance and a thin bond line, including strain gage attachment. The components mix at 100:50 by weight and provide an 8 to 12 hour pot life at room temperature. The cured material has a Tg of 220 deg C, Shore D 95 hardness, and aluminum-to-aluminum lap shear of 2,500 psi at 25 deg C.
Key features
- Thin-bond-line cementing: The system is intended for high-temperature cementing where a thin adhesive layer is required.
- Strain gage attachment: The adhesive is specifically positioned for attaching strain gages.
- High-temperature cured strength: Typical lap shear is 2,500 psi at 25 deg C and 500 psi at 260 deg C on aluminum.
Applications
- High-temperature thin-bond-line cementing
- Strain gage attachment
TDS, SDS & Technical Documents
Technical Specifications
Physical Properties
Viscosity (Part B)
powder mPa.s
Thermal Properties
Flash Point
94 °C
The flashpoint of a solvent is the lowest possible temperature at which it can vaporize to form an ignitable vapor.
Flashpoint is often confused with “autoignition temperature”, which is the temperature at which a solvent ignites without an ignition source.
Glass Transition Temperature (Tg)
220 °C
The glass transition temperature for organic adhesives is a temperature region where the polymers change from glassy and brittle to soft and rubbery. Increasing the temperature further continues the softening process as the viscosity drops too. Temperatures between the glass transition temperature and below the decomposition point of the adhesive are the best region for bonding.
The glass-transition temperature Tg of a material characterizes the range of temperatures over which this glass transition occurs.
Electrical Properties
Dielectric Strength
22 kV/mm
Dielectric strength is measured in kV per mm and is calculated by the Breakdown voltage divided by the thickness of the tested material.
Those two properties go hand in hand and while Breakdown voltage is always thickness dependent, dielectric strength is a general material property.
As an example, the dielectric strength of Polyimide is 236 kV/mm. If we place 1mm of Polyimide between two electrodes, it will act as an insulator until the voltage between the electrodes reaches 236 kV. At this point it will start acting as a good conductor, causing sparks, potential punctures and current flow.
Volume Resistivity
1 x 10^16 Ohms⋅cm
Volume resistivity, also called volume resistance, bulk resistance or bulk resistivity is a thickness dependent measurement of the resistivity of a material perpendicular to the plane of the surface.
Additional Information
Technical properties
As-supplied / before-processing properties
Typical component, mixing, and storage values before heat cure.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Resin viscosity | 30,000 to 50,000 | cP | At 25 deg C |
| Hardener form | Powder | - | At 25 deg C |
| Weight per gallon | Resin 10.4 to 10.8; hardener 14.9 to 15.3 | lb/gal | At 25 deg C |
| Mix ratio by weight | 100:50 | - | Resin:hardener |
| Pot life | 8 to 12 | h | Mixed system at room temperature |
| Recommended resin conditioning | 65 to 85 | deg C | Before adding powder hardener |
| Shelf life | 6 | months | Below 25 deg C in original sealed containers |
Technical properties
After-processing / final-state properties
Typical cured properties preserve the stated methods, substrates, and temperatures.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Cure options | 16 h at 93 deg C; 4 h at 121 deg C; 1 h at 177 deg C; or 30 min at 204 deg C | - | Time begins after the unit reaches temperature |
| Optional post-cure | 1 h at 204 deg C | - | For highest possible heat resistance |
| Hardness | 95 | Shore D | ASTM D2240 at 25 deg C |
| Glass transition temperature | 220 | deg C | ASTM E831, TMA |
| Coefficient of thermal expansion | 45 | ppm/deg C | ASTM E831 below Tg |
| Lap shear strength | 2,500 at 25 deg C; 500 at 260 deg C | psi | ASTM D1002, aluminum-to-aluminum |
| Tensile strength | 4,000 | psi | ASTM D638 at 25 deg C |
| Compressive strength | 40,000 | psi | ASTM D695 at 25 deg C |
| Dielectric strength | 560 | V/mil | ASTM D149 at 25 deg C, 125 mil specimen |
| Volume resistivity | > 1 x 10^16 | ohm cm | ASTM D257 at 25 deg C |
