Permabond 751 Flexible Cyanoacrylate Adhesive 20gm

Description

Permabond 751 is a clear, flexible cyanoacrylate adhesive developed for applications where a conventional rigid instant adhesive may not provide sufficient movement or flexibility.

Unlike traditional cyanoacrylates which typically cure to form a relatively rigid bond, Permabond 751 offers approximately 150% elongation and is designed to retain high elasticity over time.

This makes it particularly suitable for bonding flexible materials, components subjected to repeated movement, and dissimilar substrates that may experience different rates of expansion and contraction.

751 also provides good impact resistance, making it an excellent choice for assemblies exposed to vibration, thermal shock or thermal cycling.

As a single-component cyanoacrylate, no mixing is required. The adhesive fixtures in seconds on many common substrates and achieves full strength after approximately 24 hours.

Key Features & Benefits

• 150% elongation
• Maintains high elasticity over time
• Flexible cyanoacrylate technology
• Excellent for flexible and dissimilar materials
• Good impact resistance
• Suitable for components exposed to vibration
• Good resistance to thermal shock and thermal cycling
• Fast fixture times
• Clear appearance
• Solvent-free, 100% reactive formulation
• Single component – no mixing required
• Bonds a wide variety of materials
• Maximum gap fill of approximately 0.15 mm
• ISO 10993-5 cytotoxicity tested

What Materials Does Permabond 751 Bond?

Permabond 751 can bond a wide variety of substrates, including:

• Rubber and elastomers
• EPDM
• NBR rubber
• ABS
• Polycarbonate
• PVC
• Aluminium
• Mild steel
• Flexible materials
• Porous materials
• Dissimilar material combinations

For difficult low-surface-energy materials, additional surface treatment may be required.

Bonding Silicone with Permabond 751

Permabond 751 is particularly useful where silicone needs to be bonded while maintaining a high level of flexibility.

Silicone has a very low surface energy and should be treated with Permabond POP Primer before applying the adhesive.

POP significantly improves adhesion to silicone. However, the use of POP can reduce the ultimate flexibility/elongation of the adhesive.

Permabond Technical advise that, as an approximate guide, the 150% elongation of 751 may be reduced by around 30% when used with POP, potentially resulting in approximately 100% elongation.

This is still a very high level of flexibility for a cyanoacrylate and makes 751 + POP an excellent option for silicone components subjected to repeated stretching, flexing or movement.

Applications could include flexible silicone components, seals, specialist gloves and other assemblies where maintaining movement within the bonded area is important.

For more information, see our How to Bond Silicone guide.

Typical Applications

Permabond 751 is particularly suitable for:

• Flexible rubber bonding
• Silicone bonding when used with POP Primer
• Seals and flexible components
• Flexible plastics
• Components subjected to repeated movement
• Vibration-resistant assemblies
• Bonding dissimilar materials
• Components exposed to thermal cycling
• Flexible industrial equipment
• Medical device assembly

Technical Information

Property	Typical Value
Adhesive type	Flexible cyanoacrylate
Chemical composition	Ethyl cyanoacrylate
Appearance	Clear
Viscosity @ 25°C	150 mPa·s (cP)
Elongation at break	150%
Cured hardness	80 Shore A
Impact strength	15 kJ/m²
Maximum gap fill	0.15 mm
Full strength	24 hours
Fixture time on aluminium	Approx. 5 seconds
Fixture time on mild steel	Approx. 5 seconds
Fixture time on ABS	Approx. 4 seconds
Fixture time on NBR	Approx. 2 seconds
Fixture time on EPDM	Approx. 4 seconds

Figures are typical values and should not be treated as product specifications. Fixture and cure times can vary according to substrate, temperature, humidity and bond design.

Permabond 751 Bond Strength

Typical shear strengths include:

• Mild steel: 13 N/mm²
• Aluminium: 11 N/mm²
• Polycarbonate: 5 N/mm²
• PVC: 4 N/mm²
• ABS: 7 N/mm²

Actual bond strength will depend on substrate preparation, joint design and adhesive gap.

How to Use Permabond 751

Ensure bonding surfaces are clean, dry and free from grease, oil or contamination.

Apply Permabond 751 sparingly to one surface and bring the components together immediately. Maintain pressure until sufficient handling strength has developed.

For difficult substrates such as silicone, polypropylene or polyethylene, an appropriate Permabond surface treatment such as POP Primer may be required.

Cyanoacrylates generally perform best in close-fitting joints. Applying excessive adhesive will not necessarily increase bond strength and may slow curing.

Allow approximately 24 hours at room temperature for full strength before subjecting the assembly to its maximum service loads.

When Should Permabond 751 Be Used Instead of a Standard Superglue?

Choose Permabond 751 when the finished joint needs to move rather than remain completely rigid.

Standard cyanoacrylates can provide extremely high strength and very fast curing but may be unsuitable where substrates repeatedly bend, stretch or move.

Permabond 751’s combination of fast cyanoacrylate curing and approximately 150% elongation makes it particularly useful where both rapid assembly and long-term flexibility are required.

Its ability to retain elasticity over time also makes it attractive for applications where a conventional “flexible” adhesive may gradually become more rigid as it ages.

Important

Always carry out testing on the actual materials before full production, particularly when bonding silicone or other difficult substrates.

For professional or industrial use.

Refer to the latest Permabond Technical Data Sheet and Safety Data Sheet before use.