Polyurethane acrylate improves the strain recovery of pressure-sensitive adhesives
A new study shows how polyurethane acrylate (PUA) as a crosslinker significantly accelerates the strain recovery of pressure-sensitive adhesives (PSA). This opens up new possibilities for flexible electronics.
Pressure-sensitive adhesives (PSAs) are important in many industries, including electronics, automotive, healthcare and packaging, due to their ability to adhere to surfaces without the use of heat, solvents or additional processing. However, a major disadvantage of these adhesives is their low strain recovery, which is problematic for flexible electronics applications. A new study investigates how polyurethane diacrylate (PUDA) as a crosslinker significantly improves the strain recovery of PSAs.
The results show that PSAs with PUDA achieve complete recovery from strain significantly faster. While conventional PSAs crosslinked with 1,6-hexanediol diacrylate (HDDA) require a recovery time of about 61 seconds, the strain recovery time of PUDA-based adhesives is only about 2.5 seconds. This rapid recovery makes PUDA-based PSAs particularly suitable for applications under extreme load conditions, such as those found in flexible electronic devices.
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Improved adhesion and long-term stability
In addition to rapid strain recovery, the PUDA PSA also exhibited an outstanding 180° peel force of about 22.0 N per 25 mm, which is significantly higher than that of a commercial PSA, which is about 12.3 N per 25 mm. These properties were confirmed in extensive testing involving 100 cycles of strain at 20%, with the PUDA-based PSAs maintaining their performance over multiple cycles.
This study provides valuable insights into how to improve the strain recovery of PSAs and lays the foundation for the further development of adhesive technologies that will be needed in the future for flexible and highly durable applications in the electronics industry.
Source: Polymer Chemistry, Issue 7, 2025
