Department of Chemistry, University of Patras, GR-26504 Patras, Greece.
Megara Resins Anastassios Fanis S.A., Vathi Avlidas, GR-34100 Evia, Greece.
Int J Mol Sci. 2023 Jan 29;24(3):2575. doi: 10.3390/ijms24032575.
The design of self-healing agents is a topic of important scientific interest for the development of high-performance materials for coating applications. Herein, two series of copolymers of 2-hydroxyethyl methacrylate (HEMA) with either the hydrophilic ,-dimethylacrylamide (DMAM) or the epoxy group-bearing hydrophobic glycidyl methacrylate were synthesized and studied as potential self-healing agents of waterborne polyurethanes (WPU). The molar percentage of DMAM or GMA units in the P(HEMA-co-DMAMy) and P(HEMA-co-GMAy) copolymers varies from 0% up to 80%. WPU/polymer composites with a 10% / or 20% / copolymer content were prepared with the facile method of solution mixing. Thanks to the presence of P(HEMA-co-DMAMy) copolymers, WPU/P(HEMA-co-DMAMy) composite films exhibited surface hydrophilicity (water contact angle studies), and tendency for water uptake (water sorption kinetics studies). In contrast, the surfaces of the WPU/P(HEMA-co-GMAy) composites were less hydrophilic compared with the WPU/P(HEMA-co-DMAMy) ones. The room-temperature, water-mediated self-healing ability of these composites was investigated through addition of water drops on the damaged area. Both copolymer series exhibited healing abilities, with the hydrophilic P(HEMA-co-DMAMy) copolymers being more promising. This green healing procedure, in combination with the simple film fabrication process and simple healing triggering, makes these materials attractive for practical applications.
自修复剂的设计是开发用于涂层应用的高性能材料的重要科学研究课题。在此，合成了两种 2-羟乙基甲基丙烯酸酯（HEMA）与亲水性的甲基丙烯酰胺（DMAM）或含环氧基的疏水性甲基丙烯酸缩水甘油酯的共聚物，并将其作为水基聚氨酯（WPU）的潜在自修复剂进行了研究。P(HEMA-co-DMAMy)和 P(HEMA-co-GMAy)共聚物中 DMAM 或 GMA 单元的摩尔百分比从 0%变化到 80%。通过简单的溶液混合方法制备了含有 10%或 20%共聚物的 WPU/聚合物复合材料。由于 P(HEMA-co-DMAMy)共聚物的存在，WPU/P(HEMA-co-DMAMy)复合膜表现出表面亲水性（接触角研究）和吸水性倾向（吸水动力学研究）。相比之下，WPU/P(HEMA-co-GMAy)复合材料的表面亲水性低于 WPU/P(HEMA-co-DMAMy)复合材料。通过在受损区域添加水滴，研究了这些复合材料在室温下、水介导的自修复能力。两种共聚物系列都表现出修复能力，其中亲水性 P(HEMA-co-DMAMy)共聚物更有前途。这种绿色修复过程，结合简单的薄膜制造工艺和简单的修复触发，使这些材料在实际应用中具有吸引力。
