组胺改性环氧树脂及其对有机涂层性能的影响

Histamine-modified Epoxy Resin and its Effect on Properties of Organic Coatings

针对深海极端环境下涂层/金属界面结合力差的问题,通过将组胺接枝于环氧树脂E44分子链制备了能与基体金属形成化学键的活性环氧树脂(ZA-EP)。ZA-EP中组胺杂原子可通过与Fe/Fe的氧化物的空位轨道形成共用孤对电子,促使Fe^(2+)与树脂形成复合物,从而提高了涂层与金属界面的结合强度。相比于普通环氧涂层,添加活性树脂的涂层附着力明显提高,如添加3%ZA-EP后涂层附着力由6.02 MPa提高至15.36 MPa。另外,模拟深海交变压力环境下的服役结果显示,3%ZA-EP/EP涂层的饱和吸水率最低,循环一周期后仅为1.6%;72 h后的EIS结果表明,3%ZA-EP/EP涂层阻抗值仍保持稳定。组胺改性使得环氧涂层/金属界面形成化学键合作用,增强了涂层的附着力,因此ZA-EP/EP涂层具有更加优异的防护能力。

To solve the problem of poor adhesion of the coating/metal interface in deep-sea environments,active epoxy resin(ZA-EP)was prepared by grafting histamine onto the epoxy resin E44 molecular chain,which can facilitate the formation of chemical bonds with metal substrate.Histamine heteroatoms in ZA-EP can form a shared lone pair electron with the vacant orbital of iron/iron oxide,which can promote the formation of the complex of Fe2+ions with the resin,thus improving the interfacial bonding strength between the coating and the metal substrate.Compared with the ordinary epoxy coating,the adhesion of the coating containing active resin was significantly improved:for example,the adhesion of epoxy coating increased from 6.02 MPa to 15.36 MPa after the addition of 3%ZA-EP.In addition,the test results in the simulated deep-sea water under alternating pressure show that the saturation water absorption of the 3%ZA-EP/EP coating is the lowest,only 1.6%after one cycle test in 3.5%NaCl solution(by high static pressure 3.5 MPa for 12 h+constant pressure 0.1 MPa for 12 h).The EIS results after 3 cycle test(72 h)showed that the impedance of the 3%ZA-EP/EP coating remained stable.In other words,histamine modification may facilitate the formation of a chemical bond at the coating/metal interface,enhances the adhesion of the coating,thereby,the ZA-EP/EP coating has a good protective performance.