Synthesis and adhesive property study of polyoxetanes grafted with catechols via Cu(I)-catalyzed click chemistry

Mussel-inspired catechol-containing polymers have drawn great attention due to their outstanding adhesive properties. Catechol-containing polyethylene glycol (cPEG) is a well-studied catechol-containing polymer used for tissue repair. Nevertheless, catechols can only be attached to the chain ends of polyethylene glycols thus the bonding strength of the resulting polymers is limited. Aiming at solving the problem, a series of clickable polyoxetane copolymers with grafted catechol moieties were synthesized in an efficient manner. Upon addition of FeCl3 as the cross-linker, strong bonding strength of the adhesive was achieved. Polymer containing 15.5 molar percent of catechol showed the strongest bonding strength up to 5.59 MPa on sanded stainless steel. It was found that the triazole groups also contributed to the overall adhesive performance. This polyoxetane-based adhesive also displayed strong bonding ability to a variety of other substrates including porcine skin.