Phase equilibria and mixture density of polymer in supercritical fluid are used for polymer process design and molecular structure analysis in polymer science. In this study, phase equilibria and densities of 2.4 wt% d-polyethylene and 3.5 wt% poly(ethylene-co-butene)47 copolymer in ethane at high pressure were measured. High pressure phase behavior of 2.4 wt% d-polyethylene-ethane system was measured at the temperature range of 80∼150 ℃ and pressure up to 1350 bar, and the mixture density was obtained at 110, 130, and 150 ℃ and pressure below 2415 bar. The pressure-temperature equilibrium curve of 3.5 wt% poly(ethylene-co-butene)47-ethane mixture was measured at temperature below 150 ℃ and pressure below 674 bar, the mixture density was showed at 110, 120, 130, and 150 ℃ and pressure below 2415 bar. High pressure phase behavior and mixture density was compared with ethane additives, concentration of 22.6, 23.1 and 26.1 wt%, in poly(ethylene-co-butene)10-C5D12 mixtures. Phase behaviorexperiment of the three system was measured in the temperature range of 110∼150 ℃ and the pressure range of 209∼372 bar. The pressure-temperature equilibrium curve measured was compared with each of the poly(ethylene-co-butene)10-C5D12-ethane system. The poly(ethylene-co-butene)10-C5D12-26.1 wt% ethane system showed the highest phase behavior equilibrium curve. For the poly(ethylene-co-butene)10-C5D12-22.6 wt% ethane system, the mixture density at temperature of 110, 130, and 150 ℃, the pressure range of 227∼2415 bar and the density range of 0.631∼0.832 g/㎤ were measured. The mixture density of poly(ethylene-co-butene)10-C5D12-23.1 wt% ethane system was measured at the temperatures of 110, 130, and 150 ℃ and pressure below 2415 bar. Also, the mixture density at the temperature of 130 ℃ and pressure below 2415 bar and the density range of 0.563∼0.728 g/㎤ were measured for the poly(ethylene-co-butene)10-C5D12-26.1 wt% ethane system.

초임계 용매를 이용한 고분자와의 상거동 및 혼합물 밀도는 고분자 고정개발과 분자간의 구조를 해석하는데 유용한 자료로 이용된다. 본 연구에서는 고압에서 에탄(ethane)내에 2.4 wt% d-polyethylene 과 3.5 wt% poly(ethylene-co-butene)47 공중합체를 혼합한 혼합물의 상거동과 밀도를 관측하였다. 2.4 wt% d-polyethylene-에탄계의 상거동은 온도 80∼150 ℃ 범위의 압력 1350 bar 이하에서 관찰되었으며, 혼합물 밀도는 120, 130 및 150 ℃와 압력 2415 bar 이하에서 자료를 얻었다. 3.5 wt% poly(ethylene-co-butene)47-에탄 혼합물의 압력-온도 평형곡선은 온도 150 ℃ 이하와 압력 674 bar 이하에서 용해되었으며, 혼합물 밀도는 110, 120, 130 및 150 ℃와 압력 2415 bar 이하에서 얻었다. Poly(ethylene-co-butene)10-C5D12 혼합물에 에탄 함량을 각각 22.6, 23.1 및 26.1 wt% 첨가하여 고압상거동 및 혼합물 밀도를 얻었다. 상거동 실험은 온도 110∼150 ℃와 압력범위 209∼372 bar에서 관찰되었다. 측정한 온도-압력 평형곡선은 poly(ethylene-co-butene)10-C5D12-에탄계에 대한 에탄농도 22.6, 23.1 및 26.1 wt%에 따라 비교하였으며, poly(ethylene-co-butene)10-C5D12-26.1 wt% 에탄계가 가장 높은 평형곡선을 나타내었다. 또한 poly(ethylene-co-butene)10-C5D12-22.6 wt% 에탄계의 경우 온도 110, 130 및 150 ℃와 압력 227∼2415 bar 범위에서 혼합물 밀도 0.631∼0.832 g/㎤이였으며, poly(ethylene-co-butene)10-C5D12-23.1 wt% 에탄계는 110, 130 및 150 ℃와 2415 bar이하에서 혼합물 밀도를 얻었다. Poly(ethylene-co-butene)10-C5D12-26.1 wt% 에탄계는 130 ℃와 2415 bar이내에서 0.563∼0.728 g/㎤의 밀도를 얻었다.