Li Chunyin, Lei Hong, Wu Zhigang, Xi Xuedong, DU Guanben, Pizzi Antonio
Yunnan Key Laboratory of Wood Adhesives and Glued Products, College of Material Science and Engineering, Southwest Forestry University, 650224 Kunming, China.
International Joint Research Center for Biomass Materials, Southwest Forestry University, 650224 Kunming, China.
ACS Appl Mater Interfaces. 2022 May 25;14(20):23859-23867. doi: 10.1021/acsami.2c02859. Epub 2022 May 11.
Biomass-based adhesives have attracted much attention due to their eco-friendly, sustainable characteristics compared to formaldehyde-based adhesives; however, their low bonding strength and water resistance restrict their application. Thus, developing a high-performance biomass-based adhesive with excellent bonding strength and water resistance is necessary. In this work, a fully biomass-based citric acid-glucose (CAG) adhesive was produced by the esterification reaction of glucose and citric acid, which was validated by Fourier transform infrared (FT-IR), C nuclear magnetic resonance (C NMR), and liquid chromatography-mass spectrometry (LC-MS). Furthermore, the properties of the CAG adhesive were tuned considering the effects of reaction time and molar ratio of citric acid/glucose (CA/G). It was revealed that increasing the molar ratio of CA/G is more advantageous to improve the shear strength and water resistance of plywood than the reaction time. The dry and wet strengths of plywood bonded by the CAG adhesive can reach the standard requirement (≥0.7 MPa) when the molar ratios of CA/G were more than 0.6 and the reaction time was 1 h. These results were better than those bonded by the urea-formaldehyde (UF) resin. Therefore, this green adhesive shows great potential to replace the existing industrial UF resin adhesives.
与基于甲醛的胶粘剂相比，基于生物质的胶粘剂因其环保、可持续的特性而备受关注；然而，它们较低的粘结强度和耐水性限制了其应用。因此，开发一种具有优异粘结强度和耐水性的高性能生物质基胶粘剂是必要的。在这项工作中，通过葡萄糖和柠檬酸的酯化反应制备了一种完全基于生物质的柠檬酸-葡萄糖（CAG）胶粘剂，该胶粘剂通过傅里叶变换红外光谱（FT-IR）、碳核磁共振（C NMR）和液相色谱-质谱联用（LC-MS）进行了验证。此外，考虑到反应时间和柠檬酸/葡萄糖（CA/G）摩尔比的影响，对CAG胶粘剂的性能进行了调整。结果表明，提高CA/G摩尔比对提高胶合板的剪切强度和耐水性比反应时间更有利。当CA/G摩尔比大于0.6且反应时间为1 h时，用CAG胶粘剂粘结的胶合板的干强度和湿强度可达到标准要求（≥0.7 MPa）。这些结果优于用脲醛（UF）树脂粘结的结果。因此，这种绿色胶粘剂显示出取代现有工业UF树脂胶粘剂的巨大潜力。
