Preparation And Properties Of Nano-carbon Modified High Conductive Anticorrosion Coating

Conductive anticorrosion coating apply on the surface of ground steel structure, so the ground steel structure can dissipate the leakage current and prevent to be corroded by the soil, and protect the safety of grounding network, it is becoming a hot research spot in recent years. Metal conductive filler of high conductive anticorrosion coating tend to be oxidized on high current, it severely weakened coating performance, and conventional carbon materials can’t meet the requirements of high conductivity, So this paper uses the high conductivity of nanoscale carbon materials(carbon nanotubes and nano graphite)as conductive filler to prepare high conductive anticorrosion coatings which can be used for corrosion protection of ground net. The compatibility of nano-carbon materials with organic resin is poor, so they have poor dispersion in organic resin, and nano-carbon materials have large specific surface area, they prone to accumulate in the coating. At first, this paper studies the nanometer carbon conductive anticorrosion coating film-forming, then the nanometer carbon type and amount of conductive fillers on the performance impact of coating; Aimed at solve the problem of poor compatibility of filler, coupling agent modification methods on nano carbon filler is studied, discusses the handling method of coupling agent, type and adding amount on the properties of the coating. Detect them with SEM. The experimental results are as follows:1, GB has better comprehensive performance, so it is suitable as the film-forming resin of conductive anticorrosion coating; Butyl acetate and cyclohexanone with 1:1 distribution has the best diluent effect for GB, but adding amount should not exceed 40% of the resin content, so as not to affect coating corrosion resistance.2, Carbon nanotubes and nano graphite can significantly reduce the volume resistivity of coating, the percolation threshold value of carbon nanotubes is at about 2.1%, and nano graphite is about 3%. Both nano carbon materials have different modification effect of the coating because of the vast difference between the structure of them.When carbon nanotubes:nano graphite is 1:4, the percolation threshold value is 2%, they can effectively match to reduce coating volume resistivity.3, Nano carbon filler with coupling agent pretreatment have better compatibility with resin and improve their dispersion. The modification effect order of the fillers is KH550 > KH560 > JSC, when using silane coupling agent KH550 with mass ratio of 1:1, coating has the lowest volume resistivity1.94 Ω·cm, grade 1 of adhesion, and excellent corrosion resistance.4, The final formula of conductive anticorrosion coating are as follows: Film-forming resin is GB, diluent are butyl acetate and cyclohexanone with mass ratio 1:1, the filler are carbon nanotubes and nano graphite with mass ratio of 1:4, the filler should be modified by the mass ratio of 1:1 silane coupling agent KH550. The final conductive anticorrosion coating performance meet the requirements of the electric power grounding network corrosion protection.