A tannin–oxidized glucose wood adhesive with high performance

• Published in: Industrial crops and products 2024-12, Vol.222, p.119603, Article 119603
• Main Authors: Zhou, Yuchen, Li, Chunyin, Xu, Dandan, Wang, Zhinan, Chen, Zhangmin, Lei, Hong, Du, Guanben
• Format: Article
• Language: English
• Subjects: Biomass adhesive; Oxidized glucose; Tannin; Water resistance
• ISSN: 0926-6690
• DOI: 10.1016/j.indcrop.2024.119603

Tannin, as a natural polyphenol found in plant sources, has been widely employed to replace petrol-based phenol to prepare tannin-based wood adhesives. However, the development of all-biomass tannin-based wood adhesive with superior bonding strength and water resistance is still a challenge. Herein, an all-biomass tannin-based adhesive was synthesized using tannin and glucose, demonstrating enhanced bonding strength and water resistance. To improve the reactivity of glucose, part of the hydroxyl groups on the glucose molecule is oxidized to aldehyde groups. The successful oxidation of glucose and synthesis of tannin-oxidized glucose (TOG) adhesive were demonstrated by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). It was suggested that the improvement of TOG adhesive bonding properties and water resistance were caused by the formation of cross-linked network with covalent and hydrogen bonding synergies. The TOG adhesive has good water-resistance, and its residual rates can reach to 93.8 % after soaking in water for 24 h while the residual rates of tannin-glucose (T-G) adhesive only 81 %. Compared with T-G and TOG adhesives, the dry bonding strength of adhesive increased by 256.5 %, from 0.62 MPa to 2.21 MPa, the wet bonding strength of adhesive from zero to 1.97 MPa. The plywood prepared with TOG adhesive met the GB/T 17657–2022 standard for Class II plywood. This study introduces an innovative and eco-friendly method for synthesizing an all-biomass tannin- based wood adhesive, characterized by superior bonding strength and enhanced water resistance. [Display omitted] •The prepared adhesive is characterized by its full biomass composition, diverse and inexpensive raw material sources.•Produced plywood using TOG adhesive suitable for meeting the Class II plywood requirement of Chinese national standard GB/T 17657–2022.•Achieved a dry bonding strength and wet bonding strength in hot water surpassing the China National Standard for exterior use of plywood (≥0.7 MPa).