Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology, Wuhan 430068, China.
School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China.
Int J Mol Sci. 2024 Sep 30;25(19):10533. doi: 10.3390/ijms251910533.
The preparation of traditional wood-based panels mostly uses adhesives such as urea-formaldehyde resin and phenolic resin, which not only consumes petrochemical resources but also releases formaldehyde, posing potential health risks to the human body. Lignin, a natural adhesive in plant cells, is characterized by high reactivity, and it is expected to aid in the development of a new generation of green formaldehyde-free adhesives. However, current studies of lignin adhesives have revealed that while strides have been made in reducing formaldehyde emissions, its residual presence remains a concern, an issue which is compounded by inadequate water resistance. Dehydrogenated Polymer (DHP) has a lignin-like structure and good water resistance, offering a new option for the development of formaldehyde-free adhesives. In this paper, DHP and glucuronic acid were reacted with each other in a simulated hot-pressing environment to obtain DHP-glucuronic acid complex, and then the structure of the complex was characterized by infrared nuclear magnetic resonance to verify whether DHP can be efficiently connected with hemicellulose components under hot-pressing conditions. The results showed that the thermal condensation reaction of DHP and glucuronic acid can generate ester bonds at the Cα position in a simulated hot-pressing environment. This paper explores the thermal condensation mechanism of DHP and glucuronic acid, which is helpful for understanding the bonding process between adhesives and components of wood-based panels in the hot-pressing process, and provides key theoretical support for the design of more sustainable lignin adhesives.
传统木质板材的制备大多采用脲醛树脂和酚醛树脂等胶粘剂，不仅消耗石化资源，而且释放甲醛，对人体健康存在潜在风险。木质素是植物细胞中的天然胶粘剂，具有高反应性，有望帮助开发新一代绿色无甲醛胶粘剂。然而，目前对木质素胶粘剂的研究表明，虽然在降低甲醛排放方面取得了进展，但仍存在残留问题，而且耐水性能不足。脱氢聚合物（DHP）具有木质素类似的结构和良好的耐水性，为开发无甲醛胶粘剂提供了新的选择。本文在模拟热压环境中，使 DHP 与葡萄糖醛酸相互反应，得到 DHP-葡萄糖醛酸复合物，然后通过红外核磁对其结构进行了表征，以验证 DHP 是否能在热压条件下与半纤维素成分高效连接。结果表明，DHP 和葡萄糖醛酸在模拟热压环境中的热缩合反应可以在 Cα 位置生成酯键。本文探讨了 DHP 和葡萄糖醛酸的热缩合机制，有助于理解热压过程中胶粘剂与木质板材成分的键合过程，为设计更可持续的木质素胶粘剂提供了关键的理论支持。
