Study On Mechanical Properties Of Low Infrared Emissivity Coatings Cured At Room Temperature And Applied At Moderate Temperature

As the material of tail nozzle in modern vehicle, low infrared emissivity coating applied at moderate temperature has the function of protection and defense. In engineer application of practice, the coatings should be cured in low temperature. In this paper, we chose the resin through the comparison of emissivity and mechanical properties, chose the curing agent through the analysis of the kinetics of curing reaction. In order to realize the engineer application property of infrared stealth of aircraft, to design and synthesize the low infrared emissivity coating cured at 35℃, and applied at moderate temperature with good mechanical properties.This paper analyzed the influence of resin type, curing agent type, dosage and additives on the engineering application properties of moderate temperature resistant and low infrared emissivity coating cured at room temperature. We had got the optimal formula through analysis and comparison, and taken the mechanism analysis based on theories. Our main achievements were shown as follows:1.Prepared the coating with epoxy modified silicone resin, self-setting silicone resin, UV photo-curable coating, respectively cured at the same temperature, chose the better type of resin through the comparison of infrared emissivity and mechanical performance of coating, and analyzed the reason from FTIR spectra.2.Studied the curing reaction kinetics of curing agent/resin by the DSC method, determined the system of enclosed isocyanate cross-linking agent/epoxy modified silicone resin, amine curing agent/epoxy modified silicone resin can be cured at the lower temperature, through the calculation of activation energy.3.Through the comparison of the influence on infrared emissivity, glossiness, mechanical properties, temperature resistance by different agents’ type and dosage, it was concluded that for the optimal formula, when the coating was cured at room temperature, the mass ratio of phenolic-aldehyde amine and low molecular polyamide was 2:1 and the comprehensive performance was the best.4.In the system of enclosed isocyanate cross linking agent/epoxy modified silicone resin, the flexibility of coating was poorer. The addition of toughening agent made the flexibility to be 1 mm, but at the same time the hardness of coating dropped; After we increased the amount of curing agent again, hardness and flexibility of the coating were both better, but the temperature resistance of coating became poorer because the introduction of a lot of agents which were not resistant to temperature.