Yuan Hui, Wang Yushuai, Liu Zhiyong, Li Shiyu
College of Civil Engineering, Yantai University Yantai 264005 China.
RSC Adv. 2019 Aug 27;9(46):26817-26824. doi: 10.1039/c9ra04441h. eCollection 2019 Aug 23.
Herein, the effects of the amount of waterborne polyurethane, silica sol and fillers on the compressive and bending strength, temperature resistance and acid resistance of waterborne polyurethane-modified silicate-based coatings were investigated. The results indicated that the modified coating showed higher mechanical properties, impermeability and bonding properties when the amounts of polyurethane and silica sol were 10% and 4%, respectively. The room temperature strength, temperature resistance and acid resistance of the modified coating were 25.1%, 34.1% and 32.4% higher than those of unmodified coatings, respectively. Moreover, the flexibility of the coating was significantly improved. The compression-bend ratio of the modified coating was 7% higher than that of the unmodified coating. The impermeability of the modified coating was 53% higher than that of the unmodified coating. The bond strengths of the modified coatings with a concrete and an acid-resistant ceramic tile were 3.08 MPa and 5.84 MPa, respectively, which were higher than the standard value of 1.2 MPa. SEM analysis showed that the morphological structure of the coating was changed. The results showed that a dense micro-structure with an interpenetrating network was formed. EDS analysis showed that the sulfur atom was absent in the modified coating after acid storage. The MIP test showed that the porosity of the modified sample decreased and the pore distribution was improved. TGA analysis showed that the modified coating could meet the requirement of temperature resistance at 250 °C.
本文研究了水性聚氨酯、硅溶胶和填料的用量对水性聚氨酯改性硅酸盐基涂料抗压强度、抗弯强度、耐温性和耐酸性的影响。结果表明，当聚氨酯和硅溶胶的用量分别为10%和4%时，改性涂料表现出更高的力学性能、抗渗性和粘结性能。改性涂料的室温强度、耐温性和耐酸性分别比未改性涂料高25.1%、34.1%和32.4%。此外，涂料的柔韧性显著提高。改性涂料的压缩弯曲比比未改性涂料高7%。改性涂料的抗渗性比未改性涂料高53%。改性涂料与混凝土和耐酸瓷砖的粘结强度分别为3.08MPa和5.84MPa，高于标准值1.2MPa。扫描电子显微镜分析表明，涂料的形态结构发生了变化。结果表明，形成了具有互穿网络的致密微观结构。能谱分析表明，酸储存后改性涂料中不存在硫原子。汞侵入孔隙率测试表明，改性样品的孔隙率降低，孔隙分布得到改善。热重分析表明，改性涂料在250℃时能满足耐温性要求。
