본 연구에서는 삼성분계인 poly(butyl methacrylate)[PBMA]-CO₂-butyl methacrylate[BMA]혼합물에 대해 온도 36-234˚C, 압력 2,000bar까지 실험을 수행하여 상거동 자료를 얻었으며, 이때 공용매인 BMA 농도는 7.9, 16.2, 29.8 및 40.7wt%이었다. 공용매의 농도가 증가함에 따라 음의 기울기에서 양의 기울기로 변화되는 과정을 나타내었다. 그리고 PBMA-CO₂ 용액에 BMA의 농도를 55.0 wt%로 첨가하여 상거동 변화를 나타내었으며, BMA의 농도가 55.0 wt% 일 때 삼상(LLV)이 나타남을 보였다. 또한 PBMA 고분자는 CO₂2-BMA 혼합물에 대해 압력-조성관계를 35.0, 75.0 및 110.0℃에서 실험하였으며, 이때 압력은 19-158 bar 범위였다. CO₂-BAM계에 대해 동일한 압력에서 CO₂의 용해도는 온도가 증가함에 따라 감소함을 보였다. CO₂-BMA 계의 실험결과는 Peng-Robinson과 statistical associating fluid theory[SAFT]상태방정식에 모델링하였다. 온도에 독립적인 파라미터를 이용하여 두 상태식에 의해 계산한 계산치와 실험치를 비교하여 나타내었다.

Phase behavior data for ternary poly(methyl methacrylate)[PBMA]-CO₂-butyl methacrylate[BMA] are measured in the temperature range of 36 to 234℃, to pressure as high as 2,000 bar, and with cosolvent concentrations of 7.9, 16.2, 29.8, and 40.7wt%. This system changes the pressure-temperature slope of the phase behavior curves from negative to positive as the cosolvent concentration increases. The addition of 55.0 wt% BMA to PBMA- CO₂ shows the change of LLV phase behavior. The PBMA-pure CO₂ system dissolves at 243.3℃ and 1,419 bar. Pressure-composition isotherms are also shown for the CO₂-BMA at 35.0, 75.0, and 105℃ and in pressure from 19 to 158 bar. The solubility CO₂ for the CO₂-BMA system decreases as the temperature increases at constant pressure. The experimental reuslts for the CO₂-BMA system are modeled using Peng-Robinson and statistical associating fluid theory(SAFT)equation of state with temperature-independent parameters. The experimental data was compared with the calculated data by the Peng-Robinson and the SAFT equation of state for the CO₂-BMA system.

Phase Behavior Poly(buty methacrylate)-CO₂-Butyl Methacrylate System Cosolvent Effect CO₂-Butyl Methacrylate System

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