Strong, Reusable, and Self‐Healing Lignin‐Containing Polyurea Adhesives

Abstract

Reusable, self‐healable, removable, and strong bio‐based polyurea adhesives were successfully synthesized via partially substituting polyetheramine with polyetheramine‐grafted lignin and introducing a chain extender containing dynamic disulfide bonds. The polyetheramine‐grafted lignin endowed the polyurea adhesives with significantly enhanced adhesion strength on either metal or wood substrates by introducing intensive hydrogen bonding interactions; the dynamic disulfide bonds played a key role in the excellent self‐healing and reusable performance. The thermostability of polyurea adhesives was also improved by introducing lignin. This work provides a novel approach for the high‐value utilization of low‐cost lignin in recyclable adhesives with excellent comprehensive performance.

Development of a multifunctional nanocomposite film with record-high ultralow temperature toughness and unprecedented fatigue-resistance

“…Soy protein isolate (SPI) is an inexpensive and biodegradable material with good lm-forming property 23 . Lignin, one of the main recalcitrant substances in pulping black liquor, is the most abundant aromatic polymers in nature 24 . SPI grafted lignin (SPI-lignin) has a 3D complex molecular structure with abundant hydroxyl, amino, and sulfonic acid groups, which can form high density of H-bonds with PVA thus is envisioned as a promising external H-bond crosslinker 25 .…”

Self-Healing Silicone Elastomer with Stable and High Adhesion in Harsh Environments

“…As shown in Figure 4b, as the hydrogen bond crosslinking network content increased in the silicone elastomer, the adhesion gradually increased until the strongest adhesion of PDMS-4 was reached (485 kPa), which was relatively higher than that of most reported self-healable adhesive elastomers. 22,39,40 In addition, the silicone elastomer showed strong adhesion repeatability. As shown in Figure 4e, the adhesion strength of the silicone elastomer did not significantly decrease during the successive five times peeling−adhesion test with an iron sheet.…”

Lignin and Lignin-Derived Compounds for Wood Applications—A Review

“…A tensile strength of 91.2 MPa was reported for the adhesives binding single aspen wood chips according to GB/T 9846-2015 [74]. A self-healing, recoverable polyurethane adhesive with 20% lignin modified with long chain polyetheramines was presented by Liu et al (2020) [75]. The polyurethane adhesives all showed improved lap shear strengths upon addition of lignin or modified lignin, the best value being a lap shear strength of 7.8 MPa for beech wood boards in the first test (upon reusing, even higher values were achieved) [75].…”