Soybean meal (SM)-based adhesive, which is sustainable and releases no aldehyde, can play an important role in the development of green adhesives. However, natural SM-based adhesives lack water retention ability, which makes it tedious to apply in engineered materials. This work designed a polymer entanglement system by free radical polymerization of acrylamide (AAm). As a small molecule filler, succinic acid (SA) entered the polyacrylamide (PAAm) cross-linking network. The hydrophilic amide groups of PAAm can adsorb water molecules through hydrogen bonding interactions, while the introduction of SA achieved hydrogen bonding interlocking between carboxyl and amide groups on water molecules, firmly locking water molecules in the three-dimensional network of PAAm. This not only improved the cohesion of the adhesive, but also achieved excellent water retention performance.The prepressing strength of the plywood with the prepared adhesive was 1.05 MPa, which grew by 104 times in contrast to unmodified one (0.01 MPa) after the veneer was once opened and evaporated in the air for 1 h. In addition, the water content of the modified adhesive was found to be multiplied by 69.5 % after 3 days, in contrast to the unmodified adhesive. The dry and wet shear strengths of the modified adhesive were 2.47 and 1.21 MPa, which were 61.8 % and 317.2 % higher than the SM adhesive. A SM-based adhesive system that enhanced water retention while increasing strength was created, achieving excellent water retention, high bonding strength, and excellent long-term prepressing performance. As a green adhesive, this is a good reference for the further development of soy protein adhesives in engineering applications.

中文翻译：

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受水凝胶启发，用于工程应用的高保水性生物质胶粘剂


基于豆粕 （SM） 的胶粘剂具有可持续性且不释放醛类，可以在绿色胶粘剂的发展中发挥重要作用。然而，天然 SM 基胶粘剂缺乏保水能力，这使得在工程材料中的应用变得乏味。本研究通过丙烯酰胺 （AAm） 的自由基聚合设计了一种聚合物纠缠体系。琥珀酸 （SA） 作为一种小分子填料，进入聚丙烯酰胺 （PAAm） 交联网络。PAAm 的亲水性酰胺基团可以通过氢键相互作用吸附水分子，而 SA 的引入实现了水分子上羧基和酰胺基团之间的氢键互锁，将水分子牢牢锁定在 PAAm 的三维网络中。这不仅提高了胶粘剂的内聚力，而且实现了优异的保水性能。使用制备的胶粘剂的胶合板的预压强度为 1.05 MPa，与未改性的胶合板（0.01 MPa）相比，单板打开并在空气中蒸发 1 小时后增长了 104 倍（0.01 MPa）。此外，与未改性的胶粘剂相比，改性胶粘剂的含水量在 3 天后增加了 69.5%。改性胶粘剂的干湿剪切强度分别为 2.47 和 1.21 MPa，分别比 SM 胶粘剂高 61.8 % 和 317.2 %。创造了一种基于SM的胶粘剂系统，该体系在提高保水性的同时提高了强度，实现了出色的保水性、高粘合强度和出色的长期预压性能。作为一种绿色胶粘剂，这对大豆蛋白胶粘剂在工程应用中的进一步发展具有很好的参考意义。