原位聚合法制备聚苯胺改性MoS_(2)及其环氧复合涂层的防腐性能

Preparation of polyaniline modified MoS_(2) by in-situ polymerization and anti-corrosion properties of its epoxy composite coating

为提高环氧涂料的防腐性能,本文引入MoS_(2)纳米片作为阻隔剂,并在MoS_(2)纳米片表面原位聚合聚苯胺(PANI),制备了夹层结构i-PANI@MoS_(2)纳米片,利用PANI提高涂层的导电性,达到阳极钝化的效果。研究发现,当PANI与MoS_(2)的摩尔配比增大到7∶1时,MoS_(2)片层表面被PANI均匀覆盖,改性效果最好。与环氧树脂复合后,i-PANI@MoS_(2)-7纳米片在环氧树脂中均匀分散,复合涂层导电率提高,PANI与MoS_(2)起到了协同防腐作用,此时i-PANI@MoS_(2)纳米片既作为涂层中的阻隔剂,又作为电化学腐蚀保护剂,因此复合涂层具有最大的阻抗值、最大腐蚀电压以及最小的腐蚀电流密度,防腐性能优异。但PANI与MoS_(2)配比进一步增大,MoS_(2)纳米片表面的聚苯胺会发生团聚,导致复合涂层的防腐性能下降。

In order to improve the anti-corrosion performance of epoxy coatings,MoS_(2) nanosheets were introduced as barrier,and polyaniline(PANI)was in-situ polymerized on the surface of MoS_(2) nanosheets to prepare sandwich i-PANI@MoS_(2) nanosheets.PANI could improve the conductive properties of coatings,so as to achieve anode passivation.Results show that when the molar ratio of PANI to MoS_(2) was up to 7∶1,the surface of MoS_(2) nanosheets was evenly covered by PANI with the best modification effect.After compounding with epoxy resin,i-PANI@MoS_(2)-7 nanosheets were evenly dispersed in the epoxy resin.The conductivity of the composite coating was increased.It was due to the synergistic anti-corrosion effect of PANI and MoS_(2),namely i-PANI@MoS_(2) nanosheets could not only be used as physical barriers,but also as electrochemical corrosion protectors in coatings.Thus,the composite coating had the maximum impedance value,the maximum corrosion voltage,and the minimum corrosion current density with excellent anti-corrosion performance.However,with the further increase in the ratio of PANI to MoS_(2),the PANI on the surface of MoS_(2) nanosheets agglomerated,resulting in the decline in the anti-corrosion performance of the composite coating.