2004 KIChE and KSIEC Meeting
Phase Behavior of
Phase Behavior of Polycaprolactone Polycaprolactone in in Dimethyl Dimethyl Ether, Ether, Dimethyl
Dimethyl Ether + Ether + carbondioxide carbondioxide , , HCFC HCFC - - 22, HCFC 22, HCFC - - 22 + 22 + Carbondioxide Carbondioxide
Tae-Tae-HyoungHyoung Kim, Kim, JiJi-Young Park*, -Young Park*, JongJong--Sung Lim and Sung Lim and KiKi-Pung-Pung YooYoo
Hoseo University, Asan City, Korea 09:20~10:50
10. 29, 2004
Dept .of Chemical Engineering, Sogang University Dept .of Chemical Engineering, Sogang University
KIST*
KIST*
Objectives Objectives
● The phase behavior of PCL in DME, DME+CO The phase behavior of PCL in DME, DME+CO
22, , HCFC HCFC - - 22, HCFC 22, HCFC - - 22+CO 22+CO
22● CO CO
22could be used as an anti could be used as an anti - - solvent, and the cloud solvent, and the cloud
point of PS and PCL could be controlled by changing the point of PS and PCL could be controlled by changing the
concentration of CO
concentration of CO
22Introduction
Introduction – – what is the supercritical fluid? what is the supercritical fluid?
기체 기체 초임계유체 초임계유체 액체 액체 고체 고체
분자회합분자회합 (Molecular Association) (Molecular Association)
- 확산속도가 빠르다. (~100배) - 점도가 매우 낮다.
- 표면장력이 없다.
-
-밀도가밀도가높다.높다. -
-용해력이용해력이높다높다..
기체와 같은
성질
기체와 같은 성질액체와 같은 성질
액체와액체와 같은
같은성질
성질CO
CO
22카페인
카페인커피향
커피향기체 기체 초임계유체 초임계유체 액체 액체 고체 고체
분자회합분자회합 (Molecular Association) (Molecular Association)
- 확산속도가 빠르다. (~100배) - 점도가 매우 낮다.
- 표면장력이 없다.
-
-밀도가밀도가높다.높다. -
-용해력이용해력이높다높다..
기체와 같은
성질
기체와 같은 성질액체와 같은 성질
액체와액체와 같은
같은성질
성질CO
CO
22카페인
카페인커피향
커피향고체
고체 액체 액체
기체
초임계유체 초임계유체
임계 점
Carbon dioxide Water
온도 온도 [ [
ºC]ºC]
압력압력 [bar][bar]
22173.8
0.006
31 0 374
낮은
낮은
표면장력표면장력
높은높은
확산속도확산속도
낮은낮은
점도점도
높은높은밀도밀도낮은
낮은
표면장력표면장력
높은높은
확산속도확산속도
낮은낮은
점도점도
높은 높은밀도밀도액체 또는 기체 미디움 물성의 장점만을 채택하는 공정 개념
액체액체
또는또는
기체기체
미디움미디움
물성의물성의
장점만을장점만을
채택하는채택하는
공정공정
개념개념
고체
고체 액체 액체
기체
초임계유체 초임계유체
임계 점
Carbon dioxide Water
온도 온도 [ [
ºC]ºC]
압력압력 [bar][bar]
22173.8
0.006
31 0 374
낮은
낮은
표면장력표면장력
높은높은
확산속도확산속도
낮은낮은
점도점도
높은높은밀도밀도낮은
낮은
표면장력표면장력
높은높은
확산속도확산속도
낮은낮은
점도점도
높은 높은밀도밀도액체 또는 기체 미디움
물성의 장점만을
채택하는 공정 개념
액체액체
또는또는
기체기체
미디움미디움
물성의물성의
장점만을장점만을
채택하는채택하는
공정공정
개념개념
Phase Diagram of Polymer
Phase Diagram of Polymer - - Solvent Solvent
1) The large molecular size
differences between a polymer and an organic solvent
induce the complicated phase behaviors
2) In the vicinity of the solvent critical temperature(Tc), a homogeneous polymer solution can spilt into polymer-rich phase and solvent-rich phase.
(LCST behavior)
P
L
L+V LLV
LLV L+L L+L
LCST Curve UCST
Curve
T
Fig. 1. Phase behavior of polymer-solvent
Static method Static method
Advantage Advantage
●● easy to make equilibrium stateeasy to make equilibrium state
●● no cloggingno clogging
●● a small leakage availablea small leakage available
Disadvantage Disadvantage
●● fixed path lengthfixed path length
-- cannot measure the high cannot measure the high solubility of solution
solubility of solution
●● high costhigh cost
Fig. 2. Schematic diagram of static method reactor
Experimental Materials
Experimental Materials - - Polycarprolacton Polycarprolacton
Table. Physical properties of solvents and polymers
Solvent M.wt Tc(K) Pc(MPa) Company Dimethylether 46.06 400.00 5.24 Aldrich Co.
Chlorodifluoromethane 84.46 369.30 4.97 Aldrich Co.
Polymer M.wt Tm(K) Company Polycarprolacton 14,000 331.15 – 333.15 Aldrich Co.
Experimental Apparatus Experimental Apparatus
TI P
2
4
5
3
6 7
1 8
10
(1) variable-volume view cell; (2) monitor; (3) air oven; (4) CCD camera;
(5) halogen light source; (6) pressure generator; (7) magnetic stirrer;
(8) fluid transport line
Fig. 3. Schematic diagram of high-pressure variable-volume view cell
Experimental Apparatus Experimental Apparatus
Fig. 4. View of experimental variable volume view cell
Investigation of
Investigation of LCST LCST Curve Curve
Clear solution
Totally opaque Brightness
check
(a) Homogeneous Polymer Solution (b) Cloud Point Fig. 5. Visual Determination of L-LL Phase Transition
Results Results
●● PolycaprolactonePolycaprolactone + + DimethylDimethyl Ether, Ether, PolycaprolactonePolycaprolactone + HCFC+ HCFC--2222
PCL(Mw=100,000) + DME PCL(Mw =100,000) + HCFC-22
Results Results
●●PCL + DME + COPCL + DME + CO22, PCL + HCFC-, PCL + HCFC-22 + CO22 + CO22
PCL(Mw=100,000) + DME + CO2 PCL(Mw=100,000) + HCFC-22 + CO2
Concluding Remarks Concluding Remarks
●● Using variable volume view cell, visual investigation of Using variable volume view cell, visual investigation of
L-L-LL coexistence curve was performed for polymerLL coexistence curve was performed for polymer--solvent system.solvent system.
●● The correlated results are in good agreements with the The correlated results are in good agreements with the experimental data.
experimental data.
●● The molecular weight of the solvent was increased, the LCST The molecular weight of the solvent was increased, the LCST phase behavior was observed
●● COCO22 could be used as an anticould be used as an anti-solvent, and the cloud point of PCL-solvent, and the cloud point of PCL could
could be controlled by changing the concentration of CObe controlled by changing the concentration of CO22
