X光小角散射法研究超临界流体抗溶剂过程中聚苯乙烯构象变化

Small Angle X-ray Scattering Study on the Conformation of Polystyrene in the Anti-solvent Process of Supercritical Fluids

应用同步辐射X光小角散射法对超临界流体(二氧化碳+聚苯乙烯+四氢呋喃)抗溶剂过程中聚苯乙烯分子链的构象变化进行研究。结果表明:在不断加入抗溶剂(二氧化碳)过程中,高分子链发生了从无规线团的卷曲到蜷缩成球形颗粒的转变。当压强小于雾点压强pc时,高分子链发生卷曲;当压强大于pc时,高分子链蜷缩成密度均一的球形颗粒析出。

The conformation of polystyrene in the antisolvent process of supercritical fluids (compressed CO2+polystyrene+tetrahydrofuran) is studied by synchrotron radiation Xray small angle scattering(SAXS). Coiltoglobule transform of polystyrene chain is observed with increasing the concentration of CO2. It is found that polystyrene coils at the pressure lower than cloud point pressure (pc) and changes into globule with uniform density at the pressure higher than pc.