Permabond ET5441 Thermally Conductive 2-Part Epoxy, High-Temperature Metal Bonding Adhesive

Permabond ET5441 is a thixotropic, thermally conductive two-part epoxy built for bonding metal parts that run hot. It reaches full cure in 7 days at room temperature, or in 24 hours at room temperature followed by 30 minutes at 80°C (176°F). Cured bonds hold up well against motor oil, glycol, and hot or cold water.

Why Choose Permabond ET5441?

• Thermally conductive: 1.1 W/(m·K)
• High-temperature resistant: service from -55°C (-67°F), with brief exposure up to 200°C (392°F)
• 2:1 mix ratio by weight and volume
• Room temperature cure, with a faster heat-accelerated option
• Chemical resistance to motor oil, glycol, and hot or cold water
• UL94 HB flammability rating
• Meets ECSS-Q-ST-70-02C thermal vacuum outgassing screening for space materials
• Supplied in 50ml and 400ml dual cartridges

Bond Strength

*Substrate failed before the bond. Tensile strength at break (DIN 53504): 50 N/mm² (7,250 psi). Elongation at break: 2.9%. Hardness (ISO 868): 85 to 95 Shore D. Actual bond strength varies with substrate, joint design, gap and surface prep.

Built for Heat

• Thermal conductivity: 1.1 W/(m·K), so heat moves away from bonded components instead of building up at the joint
• Glass transition temperature (Tg): 65°C (149°F) after 7 days at 23°C. Rises to 113°C (235°F) with 24 hours at room temperature plus 30 minutes at 80°C.
• Coefficient of thermal expansion: 23 × 10⁻⁶/K below Tg, 111 × 10⁻⁶/K above Tg
• Hot strength: keeps 100% of room-temperature strength at 80°C (108 to 126% depending on cure schedule), 41 to 44% at 150°C, and 30 to 31% at 200°C
• Handles brief excursions to higher temperatures, such as paint baking or wave soldering, if the joint is not under heavy stress

Working Times at 23°C (73°F)

• Pot life: 150 minutes
• Working strength: 8 hours
• Full cure: 7 days

Heat speeds the cure a lot. At 80°C (176°F), full cure takes about 2 hours. ET5441 is thick (250,000 cP / 200,000 cP at 23°C), so cold 50ml cartridges can be hard to push. Warm the cartridges before dispensing through a mixing nozzle.

Recommended Accessories

For 50ml Cartridges

Maven DMA50 Manual Dispenser
A hand-operated dispenser for 50ml dual cartridges. Good for repairs, occasional use and smaller bonding jobs.

MIXPAC MBQ 05-24L Static Mixing Nozzle
Mixes the two components as they leave the cartridge for a consistent bead every time.

For 400ml Cartridges

Maven MV400-36X Manual Dispenser
A heavy-duty manual dispenser for 400ml dual cartridges. Suited to production, maintenance and fabrication work.

MIXPAC MFQ 10-24T Static Mixing Nozzle
The recommended mixing nozzle for the 400ml cartridge.

How to Use

1. Make sure bonding surfaces are clean, dry and free from grease. Degrease with acetone or isopropanol.
2. Lightly abrade aluminum, copper and copper alloys with emery cloth to remove the oxide layer.
3. Load the dual cartridge into the dispenser and guide the plunger into the cartridge.
4. Remove the cap and dispense until both components flow evenly.
5. Attach the static mixing nozzle and start dispensing.
6. Apply to one surface and join the parts within the 150-minute pot life.
7. Clamp the assembly until handling strength is reached, about 8 hours at 23°C.
8. Allow 7 days at room temperature for full cure, or speed it up with 2 hours at 80°C (176°F).

Mix large quantities with care. The reaction gives off heat. These directions follow Permabond's current ET5441 technical datasheet.

Typical Applications

• Heatsink and thermal-management component bonding
• Electronic component potting and encapsulation
• Heat exchanger assembly
• Motor and electrical component bonding
• Aerospace and space-hardware assemblies that require outgassing compliance
• Metal parts that go through paint baking or wave soldering
• General high-temperature structural metal bonding

Our Shelf Life Options

• Fresh Batch: our newest stock, with the most shelf life remaining.
• Short Shelf Life: 1 to 3 months left before the expiration date. Good value if you will use it soon.
• Recently Expired: past the printed date and sold as-is at a deep discount. Best for testing, prototypes and non-critical work. Run a test bond before relying on it.

Product Specifications

Product: Permabond ET5441
Adhesive type: Two-part epoxy (thixotropic)
Mix ratio: 2:1 by weight and volume
Part A: White epoxy resin
Part B: Dark gray amine hardener
Specific gravity: 2.1 (both parts)
Maximum gap fill: 2 mm (0.08 in.)
Pot life: 150 minutes at 23°C
Working strength: 8 hours at 23°C
Full cure: 7 days at 23°C, or 2 hours at 80°C
Thermal conductivity: 1.1 W/(m·K)
Flammability: UL94 HB
Outgassing: ECSS-Q-ST-70-02C (space material screening)
Storage temperature: 5 to 25°C (41 to 77°F)

For professional and industrial use. Keep away from strong oxidizing materials. Refer to the Safety Data Sheet for handling guidance.