Jiang Zijin, Li Lingtong, Fu Luoping, Xu Yingte, Zhang Lin, Wu Hong, Guo Shaoyun
The State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China.
Sichuan Dongshu New Materials Co., Ltd., Deyang 618000, China.
Polymers (Basel). 2024 Nov 23;16(23):3263. doi: 10.3390/polym16233263.
Structural adhesives are bonding materials that can quickly join structures with components and repair cracks. However, thermosetting polyurethane structural adhesives suffer from disadvantages such as insufficient toughness, poor aging resistance, and long curing time, which greatly limit their practical application. Herein, a polyurethane (PU) composite with excellent mechanical properties was prepared successfully via regulating the cross-linking structure and the dispersion of core-shell-rubber (CSR) particles. Various polyols were selected to improve the cross-linking density of the PU and to enhance the intermolecular forces, which can achieve the high strength and stability of the polyurethane composites. Solvent displacement was used to improve the dispersion of CSR in PU. The cured composite has ultra-high toughness and impact resistance due to the well-dispersed CSR particles. The impact strength was increased from 52.0 to 90.4 kJ/m, and the elongation at break was increased from 6.1% to 14.9%. Due to the addition of catalyst T120, this composite can be cured quickly at room temperature, reaching high strength after 30 min. In addition, these composites can resist extreme environments, such as high and low temperature changes, UV aging, high humidity and heat environment, and salt spray aging, which has potential and value for practical application. The prepared PU structural adhesive can meet the requirements of structural bonding transit and improve the production efficiency. This work proposed a novel strategy to prepare polyurethane composites with excellent mechanical properties for structural adhesive application.
结构胶粘剂是一种能够快速将结构与部件连接起来并修复裂缝的粘结材料。然而，热固性聚氨酯结构胶粘剂存在韧性不足、耐老化性差和固化时间长等缺点，这极大地限制了它们的实际应用。在此，通过调节交联结构和核壳橡胶（CSR）颗粒的分散性，成功制备了一种具有优异力学性能的聚氨酯（PU）复合材料。选择了各种多元醇来提高PU的交联密度并增强分子间作用力，从而实现聚氨酯复合材料的高强度和稳定性。采用溶剂置换法来改善CSR在PU中的分散性。由于CSR颗粒分散良好，固化后的复合材料具有超高的韧性和抗冲击性。冲击强度从52.0提高到90.4 kJ/m，断裂伸长率从6.1%提高到14.9%。由于添加了催化剂T120，这种复合材料在室温下能够快速固化，30分钟后达到高强度。此外，这些复合材料能够抵抗极端环境，如高低温变化、紫外线老化、高湿度和热环境以及盐雾老化，具有实际应用的潜力和价值。制备的PU结构胶粘剂能够满足结构粘结运输的要求并提高生产效率。这项工作提出了一种制备具有优异力学性能的聚氨酯复合材料用于结构胶粘剂应用的新策略。
