The Phase Behavior Of Supercritical Fluid And Its Application In Coating Industry

The volatile organic content (VOC) emission in coating application is an important source of air pollution. The use of supercritical carbon dioxide (scCO2) as a carrier for coating systems is a potential solution to these problems. This new technology and its theory basis were discussed in this paper.The interaction of supercritical fluid and solute was investigated at first, the partial mole volume of SCF-toluene was measured. The experiment result shows that the partial mole volume of cosolvent is maximum in supercritical zone. It prove that there must exit the interaction of solutes and supercritical carbon dioxide, it have agglomerates exit in this system. So if add cosolvent into the system, the solubility of solutes will be enhanced. On this basis, the interaction of supercritical fluid and polymer was investigated. The effect of polymer's structure, temperature and pressure on the solubility was discussed. The supercritical fluid and polymer binary system phase behavior was investigated. The effect of supercritical carbon dioxide on polymer-solvent system was investigated further. The effect of component's character, ration, temperature and pressure was discussed in detail.At last, the polymer-solvent-supercritical carbon dioxide ternary system was researched. The optimum ratio of spray coating was got by experiment. By comparing the formulation of SCF coating with common coating, the supercritical spray not only decrease the air pollution, it also increase the coating's quality.