Biocompatible Catechol‐Functionalized Cellulose‐Based Adhesives with Strong Water Resistance

Abstract Numerous traditional adhesives have good adhesion in dry environments. However, non‐environmental‐friendliness and poor water resistance largely limit their practical applications. To prepare biocompatible adhesives with strong water resistance and adhesion strength, in this paper, catechol‐functionalized cellulose‐based adhesive polymers are synthesized by grafting N ‐(3,4‐dihydroxyphenethyl)methacrylamide and methyl methacrylate onto cellulose chain through atom transfer radical polymerization (ATRP). The successful synthesis of the catechol‐functionalized cellulose‐based adhesive polymers is confirmed by FTIR and 1 H NMR. The different characteristics of the adhesive polymers, such as thermal stability, swelling ratio, biocompatibility, and adhesion strength are investigated. Strong water resistance on various substrates is realized in underwater environment for the catechol‐functionalized cellulose‐based adhesive with addition of Fe 3+ . The adhesion strength and thermal stability are enhanced when the catechol content is increased. The adhesive with catechol content of 25.4% shows the adhesion strength of 0.45 MPa for iron substrate in underwater environment. In addition, the adhesive with addition of Fe 3+ exhibits excellent adhesion in dry environment, with maximum adhesion strength of 3.50 MPa for iron substrate. The cell culture test shows that the adhesive polymers have excellent biocompatibility. The biocompatible adhesives with strong water resistance have potential application in electronic, wood, and building fields.