Preparation And Properties Of Anticorrosive And Heat Insulating Coatings

Insulation is one of the most important issues in petrochemical industry.The traditional insulation system is constructed but usually with complicated procedures,low insulation efficiency and high energy consumption.In this thesis,we describe the achievements on developing multifunctional coatings taking both anti-corrosion and heat insulation into account.The multifunctional coatings were studied by modifying the polymer resins,the functional fillers and the recipes.The coatings are found to be applicable in both low temperature operation condition?from room temperature to 200°C?and high one?from 200to 500°C?.The mechanical properties,heat resistance and anti-corrosion of the coatings were also studied.The results of the work are listed as follows.1)We prepared anti-corrosive and heat-insulating coatings with glycidyl amine epoxy resin?fl-133?,glycidyl ether epoxy resin?E-44?reactive solvent?D?and functional filler.The coatings were found to exhibit satisfactory adhesive strength and other mechanical properties,and performed well at low temperature?from room temperature to 200°C?operation condition.When the weight ratio of fl-133,E-44 and D achieves 2:4:4,the adhesion strength is up to 5.1 MPa,and the flexibility of the coating is found to be below 1 mm.The heat resistance is observed to be at a high level?150°C for 24 h?.The anti-corrosive properties were tested in 5%H₂SO₄ solution,5%NaOH solution and salt spray test,by which the coatings were found to be sufficiently anti-corrosive.The effects of hollow glass microsphere on the insulation properties of the coatings were also studied and it is found that the thermal conductivity reaches as low as 0.136 W/?m?K?when the content of filler S15 is 16 wt%.2)A simulation platform was designed and set up,to test the effect of coatings on the pipe insulation.When the external surface temperature?The fluid temperature?of piping is 160°C,The heat loss of the coated pipe was determined to be less than 190.4 W/m²,which indicates the coating has a satisfactory insulation,surficient stability and applicable reliability.3)We developed anti-corrosive and heat insulating coatings used at high temperature?from200 to 500°C?.The coatings were composed with a matrix of epoxy-modified silicone resin?E43?,a film forming agent?low temperature molten glass powder?,insulation filler?hollow glass microsphere?and other additives.The coatings are able to cure at room temperature.The impact resistance of the coating achieves over 50 cm while the flexibility reaches less than 1 mm,with a hollow glass microsphere content at 40 wt%and a volume concentration of pigment fillers at 0.69.When the content of filler S15 is 16 wt%,the coating shows a thermal conductivity coefficient as low as 0.138 W/?m?K?.The data mentioned above certificate the excellent mechanical and insulating properties of the coatings prepared.The data in the water proof test,the salt spray test?in neutral salt spray container for 60 d?,the oil proof test?submerged in RH-75 petrol for 14 d?as well as the electrochemical impedance spectroscopy indicate good anti-corrosion properties of the coatings.When heated at 500°C for 3 h,the resistance to impact of the coatings is found to be more than 35 cm,which demonstrates a good heating resistance to the coatings.