Styrenic TPE are probably the most widely used thermoplastic elastomers. There are three distinctly different main types:
Adhesive type |
Description |
Shear strength (N/mm2) |
Cyanoacrylate |
Standard ethyl |
>1.8* |
Toughened |
>1.3* |
|
Ethyl + primer |
>1.8* |
|
Two-part acrylic |
MMA |
0.4 |
Silicone |
Alkoxy silicone |
0.4 |
UV acrylic |
Visible light cure |
0.8 |
Table 4.13 Adhesive shear strengths (SBR) |
Notes: * Substrate failure |
• Styrene-butadiene-styrene block co-polymers
• Styrene-isoprene-styrene block co-polymers
• Styrene-ethylene-butylene-styrene block co-polymers [4]
From an adhesive viewpoint, these materials will often require a primer or some other kind of surface preparation for an effective bond (Table 4.14). However, there are many different blends and additives for styrenic TPE and so trials are recommended to verify the optimum adhesive/primer combination.
Table 4.14 Adhesive shear strengths (styrenic TPE)
Notes: * Substrate failure |
Again cyanoacrylates are amongst the first choice adhesives for these materials and would be suitable for many applications up to 80 °C operating temperatures.