Zhang Xin, Long Chun, Zhu Xiaobo, Zhang Xilin, Li Jianzhang, Luo Jing, Li Jingchao, Gao Qiang
State Key Laboratory of Efficient Production of Forest Resources & MOE Key Laboratory of Wood Material Science and Application, Beijing Forestry University, Beijing 100083, China.
College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
ACS Nano. 2023 Oct 10;17(19):18850-18863. doi: 10.1021/acsnano.3c03782. Epub 2023 Oct 2.
The development of formaldehyde-free functional wood composite materials through the preparation of strong and multifunctional soybean protein adhesives to replace formaldehyde-based resins is an important research area. However, ensuring the bonding performance of soybean protein adhesive while simultaneously developing thermally conductive adhesive and its corresponding wood composites is challenging. Taking inspiration from the microphase separation structure of spider silk, boron nitride (BN) and soy protein isolate (SPI) were mixed by ball milling to obtain a BN@SPI matrix and combined with the self-synthesized hyperbranched reactive substrates as amorphous region reinforcer and cross-linker triglycidylamine to prepare strong and thermally conductive soybean protein adhesive with cross-linked microphase separation structure. These findings indicate that mechanical ball milling can be employed to strip BN followed by combination with SPI, resulting in a tight bonded interface connection. Subsequently, the adhesive's dry and wet shear strengths increased by 14.3% and 90.5% to 1.83 and 1.05 MPa, respectively. The resultant adhesive also possesses a good thermal conductivity (0.363 W/mK). Impressively, because hot-pressing helps the resultant adhesive to establish a thermal conduction pathway, the thermal conductivity of the resulting wood-based composite is 10 times higher than that of the SPI adhesive, which shows a thermal conductivity similar to that of ceramic tile and has excellent potential for developing biothermal conductivity materials, geothermal floors, and energy storage materials. Moreover, the adhesive possessed effective flame retardancy (limit oxygen index = 36.5%) and mildew resistance (>50 days). This bionic design represents an efficient technique for developing multifunctional biomass adhesives and composites.
通过制备强力多功能大豆蛋白胶粘剂来替代甲醛基树脂，从而开发无甲醛功能性木质复合材料是一个重要的研究领域。然而，在确保大豆蛋白胶粘剂粘结性能的同时，开发导热胶粘剂及其相应的木质复合材料具有挑战性。受蜘蛛丝微相分离结构的启发，通过球磨将氮化硼（BN）和大豆分离蛋白（SPI）混合，得到BN@SPI基体，并与自合成的超支化反应性底物作为非晶区增强剂和交联剂三缩水甘油胺相结合，制备出具有交联微相分离结构的强力导热大豆蛋白胶粘剂。这些发现表明，机械球磨可用于剥离BN，然后与SPI结合，形成紧密粘结的界面连接。随后，胶粘剂的干剪切强度和湿剪切强度分别提高了14.3%和90.5%，达到1.83和1.05 MPa。所得胶粘剂还具有良好的热导率（0.363 W/mK）。令人印象深刻的是，由于热压有助于所得胶粘剂建立热传导路径，所得木质复合材料的热导率比SPI胶粘剂高10倍，其热导率与瓷砖相似，在开发生物导热材料、地热地板和储能材料方面具有优异的潜力。此外，该胶粘剂具有有效的阻燃性（极限氧指数=36.5%）和防霉性（>50天）。这种仿生设计是开发多功能生物质胶粘剂和复合材料的有效技术。
