Korean Chemical Engineering Research, Vol.42, No.3, 311-317, June, 2004
고압상태의 다양한 용매내에서 poly(L-lactide)와 polycaprolactone의 상거동
Phase Behavior of Poly(L-lactide) and Polycaprolactone in Various Solvents at High Pressure
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초록
Variable volume view cell이 장착된 상평형 장치를 사용하여 고압 상태의 다양한 용매내에서 생분해성 고분자인 poly(L-lactide)(PLA)와 polycaprolactone(PCL)의 cloud point를 측정하였으며, 이 때 사용된 용매는 HCFC-22, HFC-23, HFC-32, HFC-125, HFC-143a, HFC-152a, HFC-227a, DME(dimethylether)였다. Poly(L-lactide)의 경우, DME와 HCFC-22에 대해 25.0 MPa 이하의 압력에서 잘 용해되었고 HFC-23, HFC-32, HFC-152a에 대해 53.2-116.02 MPa범위의 압력에서 용해되었다. 이들 용매내에서 Poly(L-lactide)은 분자량의 변화 (M.W.=80,000, 110,000, 230,000)에 따른 cloud point를 측정하였다. 그러나 HFC-125, HFC-143a, HFC-227ea에 대해서는 온도 413.15 K와 압력 160 MPa까지의 범위에서도 용해되지 않았다. Poly(L-lactide)의 cloud point는 HCFC-22, HFC-23, DME를 용매로 사용한 경우에 LCST(lower critical solution temperature)형태의 상거동을 나타내었으며, HFC-32과 HFC-152a를 용매로 사용한 경우에는 UCST(upper critical solution temperature)형태의 상거동을 나타내었다. Polycaprolactone의 경우, HCFC-22, HFC-143a, DME에 대해서는 36.9 MPa이하에서 비교적 잘 용해되었고 HFC-152a에 대해 126.31-151.45 MPa의 범위에서 용해되었으며 HFC-32, HFC-125, HFC-227ea에서는 413.15 K와 압력 160 MPa까지의 범위에서도 용해되지 않았다. Polycaprolactone의 cloud point는 HCFC-22, HFC-143a, DME를 용매로 사용했을 경우에 LCST형태의 상거동을 나타내었으며, HFC-152a를 용매로 사용했을 때에는 UCST형태의 상거동을 나타내었다.
Cloud points of poly(L-lactide) and polycaprolactone in chlorodifluoromethane(HCFC-22), trifluoromethane(HFC-23), difluoroethane(HFC-32), pentafluoroethane(HFC-125), 1,1,1-trifluoroethane(HFC-143a), 1,1-difluoroethane(HFC-152a), 1,1,1,2,3,3,3-heptafluoropropane(HFC-227ea) and dimethylether(DME) at high pressure were measured using the variable volume cell apparatus for. L-PLA was dissolved well in DME and HCFC-22 below 25.0 MPa, and dissolved in HFC-23, HFC-32, and HFC-152a in the range of 53.2-116.02 MPa but, it was not dissolved in HFC-125, HFC-143a, and HFC-227ea even at 413.15 K and 160 MPa. The cloud point of L-PLA was measured with L-PLA molecular weight(M.W.=80,000, 110,000, 230,000). The cloud point of L-PLA exhibited LCST(lower critical solution temperature) behavior in DME, HCFC-22, and HFC-23 and exhibited UCST(upper critical solution temperature) behavior in HFC-32 and HFC-152a. On the other hand, polycaprolactone(PCL), it was dissolved well in HCFC-22, HFC-143a, and DME below 36.9 MPa, and dissolved in HFC-152a in the range of 126.31-151.45 MPa but, was not dissolved in HFC-23, HFC-32, HFC-125, HFC-134a, and HFC-227ea even at 413.15 K and 160 MPa. Cloud point of L-PCL exhibited LCST behavior in HFC-143a, and exhibited UCST behavior in HFC-152a.
- Angus S, Armstrong B, Reuck KM, "International Thermodynamic Tables of the Fluid State (CO2)," Pergamon Press (1976)
- Zhao X, Watkins R, Barton SW, J. Appl. Polym. Sci., 55(5), 773 (1995)
- Kajimoto O, Chem. Rev., 99(2), 355 (1999)
- Tucker SC, Chem. Rev., 99(2), 391 (1999)
- Subramaniam B, Rajewski RA, Snavely K, J. Pharm. Sci., 86(8), 885 (1997)
- Yeo SD, Kim MS, Lee JS, J. Supercrit. Fluids, 25, 143 (2000)
- Lee YW, HWAHAK KONGHAK, 41(6), 679 (2003)
- Hanney JB, Hogarht J, Proc. Roy. Soc., 29, 324 (1879)
- Gallagher PM, Coffey MP, Krukonis VJ, Klasutis N, Johnston KP, Penninger JML, Supercritical Fluid Science and Technology, ACS Symposium Series 406, ACS, Washington, DC, 334-354 (1989)
- McHugh MA, Krukonis VJ, Supercritical Fluid Extraction: Principles and Practice, 2nd ed., Butterworth-Heinemann, Boston (1994)
- Lee JM, Lee BC, Lee SH, J. Chem. Eng. Data, 45, 851 (2000)
- Lee JM, Lee BC, Hwang SJ, J. Chem. Eng. Data, 45, 1162 (2000)
- Kuk YM, Lee BC, Lee YW, Lim JS, J. Chem. Eng. Data, 46, 1344 (2001)
- McLinden M, Klein S, Lemmon E, Peskin A, NIST Thermodynamic and Transport Properties of Refrigerants and Refrigerant Mixtures Database (REFPROP), Ver. 6.01, National Institute of Standards and Technology, Gaithersburg, Maryland (1998)
- Reid RC, Prausnitz JM, Poling BE, The Properties of Gases and Liquids, McGraw-Hill, New York (1987)