Room-Temperature Curing of Cellulose Adhesive via Freeze–Thaw-Induced In Situ Cross-Linking for Bonding Wood or Bamboo

The development and utilization of cellulose-based adhesives are important trends in the field of biobased wood adhesives, given the cost-effectiveness and abundance of raw materials. However, achieving reliable adhesion and water resistance of cellulose-based adhesives under ambient curing conditions remains a challenge. In this study, an adhesive cured at room temperature is synthesized via freeze–thaw in situ cross-linking of aminated cellulose (AC) and epoxidized cellulose (EC) in a sodium hydroxide solution. Throughout the freeze–thaw process, polymer chains participate in the nucleation and growth of crystalline domains, leading to physical cross-linking between cellulose chains. Ultimately, a dual cross-linking network is formed at both micro- and nanoscales, consisting of chemical and physical cross-links. The wet lap shear strength of the AC–EC adhesive in bamboo was reached at 3.95 MPa. Notably, the AC–EC adhesive serves as an effective cold-curing adhesive suitable for bonding various woods and bamboo and achieves excellent water resistance. According to cost and energy consumption calculations during ambient curing, the AC–EC adhesive exhibits an attractive economic efficiency. The AC–EC adhesive product has potential development prospects and is of significant importance for mitigating energy consumption and carbon emissions in the artificial board industry.