Harsh environment resistible and recyclable thermoplastic polyurea adhesive based on stable and density hydrogen bonds

Abstract

Adhesives are crucial in a variety of applications, including transportation, building, electronics, aerospace and even human organs etc. However, tens of millions of tons of adhesives used world widely couldn’t be recycled due to the chemically crosslinked structure, especially for those used in harsh environments. Here, we synthesized a self-healing thermoplastic polyurea with ultra-high hydrogen bonding by ending capped with UPy and excellent harsh environment resistible and recyclable capability by utilizing PDMS as the only soft segment. For a property balanced sample, PDMS-12, it exhibited high degree of hydrogen bonding association of 92.5 % at 30 ℃ and gradually decayed after 80 ℃, after which its adhesion was stimulated as revealed by rheological test. If the pure PDMS-12 was immersed in water, pH = 1 acid, pH = 14 alkali, oil, and simulated seawater for up to 30 days, its initial adhesion strength declined between 48 % and 70 %. When it was already glued between different matrixes, the lap shear strength dropped by 0.7 % to 80 %, depending on the types of matrixes and liquid environments. Nonetheless, the remaining adhesion strength was always strong enough to lift weights of ∼ 5.0 kg and can be reused after cleaning. What’s more, a 0.5 mm glue coating could successfully protect a glass bulb from an impact of 0.5 kg weight at approximately −196 ℃, proving its potential application in fragile fields like electrical industry.