Understanding SPUR Hybrids: Standard, High Modulus, and Low Modulus Variants

In the world of advanced materials and adhesives, SPUR (Silane-terminated Polyurethane) hybrids have gained significant traction for their unique properties and versatility. SPUR hybrids combine the advantageous characteristics of both polyurethanes and silicones, offering superior performance in various applications. This blog post will delve into the differences between standard SPUR hybrids, high modulus SPUR hybrids, and low modulus SPUR hybrids, and explore their specific use cases.

What are SPUR Hybrids?

SPUR hybrids are innovative materials that blend the mechanical properties of polyurethanes with the weathering resistance and flexibility of silicones. These hybrids are created by terminating polyurethane chains with silane groups, resulting in materials that cure through moisture in the air to form durable and elastic bonds. SPUR hybrids are known for their excellent adhesion, flexibility, and resistance to weathering, making them ideal for a wide range of applications.

Standard SPUR Hybrids


  • Flexibility and Elasticity: Standard SPUR hybrids offer a balanced mix of flexibility and elasticity, making them suitable for general-purpose applications.
  • Adhesion: They provide strong adhesion to various substrates, including metals, plastics, glass, and ceramics.
  • Weather Resistance: Standard SPUR hybrids exhibit good resistance to UV radiation, moisture, and temperature fluctuations.
  • Cure Speed: These materials cure at a moderate rate, which is suitable for many industrial and construction applications.

Use Cases:

  • Construction and Building: Used in sealing joints, windows, and doors due to their balanced properties.
  • Automotive: Employed in bonding and sealing components where moderate flexibility and good adhesion are required.
  • Industrial Assembly: Suitable for general-purpose bonding and sealing tasks.

High Modulus SPUR Hybrids


  • Stiffness and Strength: High modulus SPUR hybrids are characterized by their increased stiffness and tensile strength, making them less flexible but more robust.
  • Load-Bearing Capacity: These hybrids are designed to bear higher loads and provide greater structural integrity.
  • Durability: Enhanced durability under mechanical stress and exposure to harsh environments.

Use Cases:

  • Structural Bonding: Ideal for applications requiring strong, load-bearing bonds, such as in structural glazing and façade construction.
  • Heavy-Duty Industrial Applications: Used in bonding heavy machinery parts and components where high strength and minimal flexing are critical.
  • Transportation: Employed in the aerospace and marine industries for applications that demand high mechanical strength and resistance to extreme conditions.

Low Modulus SPUR Hybrids


  • High Flexibility: Low modulus SPUR hybrids are significantly more flexible and elastic compared to standard and high modulus variants.
  • Movement Accommodation: They can accommodate greater movement and expansion, making them ideal for dynamic joints.
  • Softness: These hybrids are softer, which helps in reducing stress on bonded joints.

Use Cases:

  • Expansion Joints: Perfect for use in expansion joints in buildings and bridges where significant movement is expected.
  • Weatherproofing: Used in weatherproofing applications where materials need to flex and expand without losing their sealing properties.
  • Vibration Damping: Employed in applications requiring vibration and sound damping due to their softness and flexibility.

Comparison Summary

Property/Use Case Standard SPUR Hybrids High Modulus SPUR Hybrids Low Modulus SPUR Hybrids
Flexibility Moderate Low High
Tensile Strength Moderate High Low
Adhesion Good Excellent Good
Weather Resistance Good Excellent Good
Cure Speed Moderate Slower Faster
Typical Applications General construction, automotive Structural glazing, heavy-duty industrial Expansion joints, weatherproofing, vibration damping


Understanding the differences between standard, high modulus, and low modulus SPUR hybrids is crucial for selecting the right material for your specific application. Standard SPUR hybrids offer a balanced performance for general-purpose use, high modulus hybrids provide superior strength and durability for structural applications, and low modulus hybrids offer exceptional flexibility and movement accommodation. By choosing the appropriate SPUR hybrid, you can ensure optimal performance and longevity in your projects.

Learn more about our PRO Range of Hybrids at https://www.bonditusa.com/collections/pro-range-hybrids


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