基材处理体系对京沪高铁聚脲涂层附着力影响的研究

Influence of substrate preparation systems to the adhesion of beijing-shanghai high speed railway polyurea coating

针对冬季京沪高速铁路喷涂聚脲施工后,聚脲涂层与基材处理剂之间粘结力不高,甚至出现聚脲涂层大面积脱落的现象,分析了基材处理剂对聚脲涂层脱落的影响,提出了应用弹性聚氨酯类基材处理体系(QTECH-112系统)替代以往大量使用的环氧底涂(EP)体系的观点。对QTECH-112体系和EP体系的附着力进行对比分析,结果表明,在选用环氧胶粘剂及室内养护的条件下,E胶对二者的附着力1 d都达到3 MPa以上,18 d二者都达到8 MPa以上的高附着力;在室外养护条件下,3 d后二者都达到3MPa以上的附着力。通过静态应力分析发现,环氧在低温下具有很大的应力集中。对测试基材附着力的胶粘剂种类进行分析比对表明,改性丙烯酸酯室温快速固化胶粘剂不适合于QTECH-112系统。

Aiming at the phenomenon occurred after polyurea coating applying in the current Beijing-Shanghai high-speed railway project, i.e. poor bond strength between polyurea layer and the treated substrate layer, and even large areas of polyurea layer shedding,influence of substrate processing agent on the shedding of polyurea layer was analyzed and idea of applying new elastic polyurethane substrate processing system （QTECH-112 system） instead of traditional epoxy primer （EP） system was put forward. The adhesion strength of QTECH-112 system and EP system was compared and analyzed. The results showed that under the condition of using epoxy adhesive and indoor curing, the adhesion strength of E glue for the two system is over 3 MPa after 1 day,and is over 8 MPa after 18 days. Under the condition of outdoor curing, the adhesion strength for both can reach over 3 MPa after 3 days. The static stress analysis results show that epoxy at low temperature has a large micro-strain. At the same time,the adhesive types for testing the adhesion strength of the substrate were compared and analyzed. The results show that the modified acrylic adhesive cured fast at room temperature is not suitable for QTECH-112 System.