College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
ACS Appl Bio Mater. 2021 Sep 20;4(9):7314-7321. doi: 10.1021/acsabm.1c00825. Epub 2021 Sep 1.
Adhesives are extensively used in furniture manufacture, and most currently utilized furniture glues are formaldehyde-based chemicals, which emit formaldehyde throughout the entire life of the furniture. With increasing concerns about formaldehyde emission effects on human health, formaldehyde-free and environmentally friendly wood adhesives from bio-based resources are highly desired. In this study, we developed an eco-friendly, high-strength, and water-based wood adhesive from one-pot coacervation of the hierarchical self-assembly of folic acid (FA, a biomolecule, vitamin B9) with a commercially available biocompatible polymer-branched poly(ethylene imine) (b-PEI). The coacervation is caused by multiple hydrogen bonds between b-PEI and the stacks of FA quartets, which demonstrates a continuous robust 3D network, thus realizing adhesion and cohesion behaviors. This coacervate has the strongest adhesion toward wood compared with other substrates. The long-lasting shear bonding strength is up to 3.68 MPa, which is much higher than that of commercial super glue, but without releasing any toxic components. Since all the fabrication and application processes are under ambient conditions without any heating and high-pressure procedures, this work provides a facile yet powerful strategy to develop formaldehyde-free, eco-friendly, and high-performance bio-based waterborne adhesives for wood bonding.
胶粘剂在家具制造中被广泛使用，目前大多数使用的家具胶都是基于甲醛的化学物质，这些化学物质在家具的整个生命周期中都会释放甲醛。随着人们对甲醛排放对人体健康影响的担忧日益增加，人们迫切希望使用来自生物基资源的无甲醛、环保型木材胶粘剂。在这项研究中，我们通过叶酸（FA，一种生物分子，维生素 B9）与市售生物相容聚合物支化聚乙烯亚胺（b-PEI）的分级自组装一锅共凝聚，开发了一种环保、高强度、水性木材胶粘剂。b-PEI 与 FA 四方堆叠之间的氢键导致共凝聚，从而形成连续的强 3D 网络，从而实现了粘附和内聚行为。与其他基材相比，这种共沉淀物对木材具有最强的粘附力。持久的剪切粘结强度高达 3.68 MPa，远高于商业超级胶，但不会释放任何有毒成分。由于所有制造和应用过程都在环境条件下进行，无需加热和高压处理，因此这项工作为开发无甲醛、环保、高性能的生物基水性木材胶粘剂提供了一种简单而强大的策略。
