基于二硫键的水性聚氨酯/聚丙烯酸酯自修复材料的制备及性能

Preparation and Properties of Waterborne Polyurethane/Polyacrylate Self-Healing Materials Based on Disulfide Bond

以聚四氢呋喃醚二醇(PTMEG)和异佛尔酮二异氰酸酯(IPDI)为反应单体,2,2-二羟甲基丙酸(DMPA)、1,4-丁二醇(BDO)、2,2-二硫二乙醇(HEDS)为扩链剂,制备了含有二硫键的水性聚氨酯(WPUS)。再与聚丙烯酸酯(PA)乳液物理共混制备了一系列不同配比的自修复型水性聚氨酯/聚丙烯酸酯(AWPUS)复合材料。采用红外光谱、拉曼光谱、粒径分布、分光光度计、X射线衍射、热重分析、力学性能、扫描电镜及偏光显微镜等分析了复合材料的微观结构和组分、热稳定性及自修复性能,并探究了PA/WPUS的不同配比对胶膜自修复性能的影响。结果表明,PA的引入显著提高了材料的自修复效率;在60℃,修复效率由6 h修复73.4%提高至2 h修复81.7%;当PA/WPUS质量比为3/7时,拉伸强度和拉伸应变分别为16.8 MPa和704%,加载-卸载循环5次后,应力恢复率达到84.3%;具有良好的热稳定性和可再加工性,综合性能优异。

Aqueous polyurethane containing disulfide bond(WPUS) was prepared by using PTMEG and IPDI as monomer, DMPA, BDO and HEDS as chain extender. A series of self-healing waterborne polyurethane/polyacrylate(AWPUS) composites with different proportions were prepared with polyacrylate(PA) emulsion by physical blending. FT-IR, Raman spectroscopy, particle size distribution, UV-vis, XRD, TGA, mechanics, SEM and polarizing microscope were used to analyze the microstructure, composition, thermal stability and self-healing performance of the composites. The effects of PA/WPUS ratio on the self-healing performance of the films were also investigated. The results show that the introduction of PA can significantly improve the self-healing efficiency of the materials. At 60 ℃, the repair efficiency is increased from 73.4% in 6 h to 81.7% in 2 h. When the PA/WPUS mass ratio is 3/7, the tensile strength and strain are 16.8 MPa and 704%, respectively;after 5 loading-unloading cycles, the stress recovery rate reaches 84.3%, showing good thermal stability, reprocessability and excellent comprehensive performance.