| Most of the infrared coating of existing all have the problem of low infrared emissivity and peeling what caused by the glue is insufficient.For this task,it is rush to obtaining some desirable infrared coatings with high binding strength and infrared emissivity.The polyurethane is a burgeoning organic polymer material,and the infrared coating of polyurethane shows excellent adhesive property,and the service life reach to 15 years,in addition,its lower cost and simpler with using,has been applied in the field of military development,architectural design and energy conservation with environment protection.In this paper,the infrared coatings were successfully prepared by the Zn,Fe and Cu doped polyurethanes,respectively.Meanwhile,the coatings were coated onto aluminum sheets,which were solidified at different temperatures.The characterization of coatings reveals that the enhanced infrared emissivity of coatings is attributed to the carbonization of polyurethanes and the oxidation of metals,and the splice between coatings and substrates is very strong.The main contents could be summarized as follows:(1)Infrared coatings were successfully obtained through use of polyurethanes of excellent bonding properties,zinc powder,iron powder,copper powder and butyl acetate.Meanwhile,the coatings were coated onto aluminum sheets of 3 cm × 3 cm,which were solidified at room temperature for 24 hours,and then were further solidified at 150 ℃>250 ℃ and 350 ℃ for 1 hours,respectively.The morphology and structure were characterized by scanning electron microscopy(SEM),X-ray diffiraction(XRD),fourier transform infrared spectrometer(XRD)and microscopes raman spectrometer(Raman).The absorption ability with near-infrared of infrared coatings was measured by ultraviolet-visible spectroscopy(UV-Vis),and the infrared emissivity inside 1～22 μm of coatings was measured by infrared emissivity measurement instrument.Moreover,the firmness of coatings was measured by QFH paint film scriber.The results indicate that the enhanced infrared emissivity of coatings is attributed to the carbonization of polyurethanes and the oxidation of metals,and the emissivity of infreared coating what mix zinc is between.083 and 0.90;the emissivity of infreared coating what mix iron is between.088 and 0.93;then the coating of mix copper powder exhibits ultra-high infrared emissivity,it can reach up to 0.86～0.94.(2)The results of above-mentioned three experiments exhibits:The oxidation of copper sheet can effectively enhance the infrared emissivity of coatings.The copper was oxidized by the mixed solvent of potassium sulphate,sodium hydroxide and deionized water,which was ultrasound and not ultrasound,respectively.The morphology and structure of copper sheet what was oxidized were characterized by SEM,XRD,FT-IR and Raman,and the infrared emissivity inside 1～22 μm with oxidation layer of copper sheet was comprehensively analyzed by infrared emissivity measurement instrument.The results indicate that the better oxidation layer produce in the surface of copper sheet by reacting 20 minutes at 40 ℃.Furthermore,The surface of copper sheet has no large particulate matter after ultrasonic treatment,and has a more compact structure,which infrared emissivity inside 1～22μm can attain to 0.84.In this experiment,preparation of the infrared coating by the methods of adulteration inside polyurethanes and the oxidation of metals.The morphology structure and infrared emissivity of products were measured by various test instruments.The results indicate that the coating of polyurethanes doped copper powder exhibits excellent adhesion,and the infrared emissivity can attain to 0.94. |
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