Study On The Interaction Between Supercritical Fluid And Solute, And On The Phase Behavior Of Coating Matrix In Supercritical Fluid

The volatile organic content (VOC) emission in coating application is an important source of air pollution. In this paper, we had theoretical study on developing green coating for supercritical carbon dioxide in place of poisonous solvent in order to prevent environment pollution.The interaction of supercritical fluid (SCF) and solute was investigated at first, the partial molar volume of SCF-n-butyl acetate was measured. The experiment result shows that there must be the interaction of solutes and supercritical carbon dioxide, and molecular congeries in the system, so it results in partial density increasing and the solubility of solutes will be enhanced. Thereby there is theoretical basis for supercritical carbon dioxide dissolving into polymer resin.At last, study on the phase behavior of acrylic acid resin or high chloridized polyethylene (HCPE)-CO2-cosovlent was made, which shows rules about effect of component's character, ratio, temperature and pressure on the phase behavior. Effect of temperature and pressure on CO2 solubility is discussed, and mechanism is studied for co-solvent to increase the solute solubility. In the end, the ternary phase diagram of coating resin-solvent-CO2 was plotted. The component ratio of supercritical spray coatings was fixed, and the reason of different diagram for different coating resin was interpreted, which provided the theoretical basis for the application of supercritical CO, coating.