UV-curing polyurethane pressure-sensitive adhesive with high shear strength and good adhesion properties inspired by spider silk

• Published in: Progress in organic coatings 2024-01, Vol.186, p.107963, Article 107963
• Main Authors: Liu, Zhijun, Yuan, Guoming, Diao, Wenjie, Zhang, Yaodong, Jiao, Enxiang, Shi, Jun, Wu, Kun
• Format: Article
• Language: English
• Subjects: Acylsemicarbazide; Hydrogen bond; Polyurethane pressure-sensitive adhesives; Spider silk
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2023.107963

It is a challenge to develop polyurethane pressure-sensitive adhesive (PU-PSA) simultaneously with good cohesion and adhesion properties. Inspired by the structure of multiple hydrogen bonds in spider silk, we introduced Acylsemicarbazide (ASCZ) moiety that can form multiple hydrogen bonds in the polymer network into PU-PSA. The characteristic absorption peaks of ester groups at 1600–1780 cm−1 were analyzed in FTIR testing, and the results showed that ASCZ formed multiple hydrogen bonds in PU-PSA, and the hydrogen bond content increased with the increase of ASCZ content. In particular, PUA-AD20% with 24.3 % hydrogen bond content showed higher shear strength (0.51 MPa) and debonding energy (3.3 KJ m−2). Rheological tests showed that PU-PSA storage modulus and loss modulus increased with increasing frequency, which was highly frequency dependent. Therefore, as dynamic and reversible sacrificial bonds, hydrogen bonds can dissipate energy efficiently and resist external forces. In addition, the ASCZ component also provided PU-PSA with the polar groups required for adhesion. Therefore, PUA-AD20% had excellent adhesion properties. Compared to PUA, PUA-AD20% tack and peel strength increased by 36.1 % and 146.8 %, with values of 4.9 N and 11.6 N, respectively. In summary, this work offered a simple and versatile approach to designing PU-PSA with outstanding overall performance. [Display omitted] •Inspired by the structure of spider silk, we designed a simple and fine molecular structure for PU-PSA.•Multiple hydrogen bonds can improve the cohesion strength and adhesion properties of PU-PSA.•PU-PSA has a high cohesive strength of 0.52 MPa and good adhesion strength.•PU-PSA uses ultraviolet curing method, the production process is more rapid and environmental protection.