水杨酸在CO_2-乙酸乙酯体系中重结晶过程的相平衡及结晶形态

PHASE EQUILIBRIA OF CO_2-ETHYL ACETATE-SALICYLIC ACID SYSTEM AND RECRYSTALLIZATION OF SALICYLIC ACID

在308．15K和318．15K温度下、0～8MPa压力范围内，研究了二氧化碳一乙酸乙酯-水杨酸体系的相平衡．结果表明，水杨酸在液相中的浓度随体系压力升高而降低，随温度升高而增大．用CO2作抗溶剂可以使乙酸乙酯中的水杨酸沉淀结晶．在相平衡研究的基础上，研究了水杨酸在CO2-乙酸乙酯中的结晶，得到针状空心晶体．

The phase equilibria of CO2-ethyl acetate-salicylic acid system were investigated at 308.15 K and 318.15 K in the pressure range from 1 to 8 MPa. The concentration ofsalicylic acid in liquid phase increases slightly with temperature and decreases with pressure.CO2 can be used as antisolvent to recrystallize salicylic acid from ethyl acetate. On the basiso f the phase equilibria, the recrystallization of salicylic acid was performed by gas antisolventprocess, and hollow needle crystal was obtained.