不同粒径PANI/SiO_(2)对环氧涂层防腐性能的影响

Effect of PANI/SiO_(2) Particle Size on Anti-corrosion Properties of Epoxy Coating

采用原位聚合,在不同粒径的SiO_(2)表面包覆了聚苯胺(PANI),以制备PANI/SiO_(2)颗粒。包覆后的SiO_(2)颗粒由白色变为墨绿色,红外光谱的研究表明,PANI已经包覆到SiO_(2)颗粒表面。采用热重研究PANI的包覆率,结果表明包覆率随着SiO_(2)粒径的减小而增加,1250目SiO_(2)颗粒PANI的包覆率达到1.76%(质量分数,下同)。将PANI/SiO_(2)颗粒添加到环氧树脂涂层中制备防腐涂层,研究发现,SiO_(2)的粒径对涂层的力学性能和防腐性能有至关重要的影响。随添加颗粒粒径的增加,涂层的附着力、耐冲击性以及耐磨性会进一步增加,而涂层硬度减小。添加400目PANI/SiO_(2)颗粒所制备的环氧涂层,结构致密,将其浸泡在3.5%NaCl水溶液中30 d,涂层依然能够发挥很好的防腐作用。

Silicon dioxide(SiO_(2)) particles with different sizes were coated by polyaniline(PANI)using in-situ polymerization and then the appearance of SiO_(2) changed from white to dark green.The results of FTIR showed that PANI had coated on the surface of SiO_(2) particles.The coating rate of PANI was studied by thermogravimetry and the results showed that the coating rate increased with the decrease of SiO_(2) particle size.The PANI coating rate of 1250 meshes SiO_(2) particles reached 1.76%(mass fraction,the same below).Anti-corrosion coating was prepared by adding PANI/SiO_(2) particles into the epoxy resin matrix.It was found that the particle size of PANI/SiO_(2)has an important influence on the mechanical and anti-corrosion properties of the coating.With the increase of particle size,the adhesion,impact resistance and wear resistance of the coating increased but the hardness of the coating decreased.The structure of coating by adding 400 meshes PANI/SiO_(2)particles was compact and this coating still showed good anti-corrosion properties immersing in 3.5%NaCl solution after 30 days,which should be related to the PANI passivation to metal.