phase behavior and modeling of co + 2,2,2- trifluoroethyl

Phase behavior and modeling of CO2 + 2,2,2-trifluoroethyl methacrylate and CO2 + poly (2,2,2-

trifluoroethyl methacrylate) systems

권소영권소영, 배 원, 변헌수1, 김화용*, 배 원, 변헌수 , 김화용*

서울 대학교 응용 화학부 열물성 연구실

여수대학교 화학공학과1

E-mail : [email protected]

Thermophysical Properties Lab.

Objectives – Applications of poly (TFEMA)

Fabric protectors

Thermo-

plastics

Electro-coatings

Fiber optics

Surface

coatings

Poly (TFEMA)


SCFmonomer

초임계 유체를 이용한고분자 합성

Mole fraction of CO2

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Pres

sure

(bar

)

0

20

40

60

80

100

120

140

160

180

200

324.8K 335.1K345.5K355.8K

Temperature(oC)

40 60 80 100 120 140 160 180 200

Pres

sure

(bar

)

0

500

1000

1500

2000

2500

NVP 24.8 wt%NVP 29.6 wt%NVP 34.6 wt%

Binary mixture of CO2+monomer or polymer

Ternary mixture of Polymer + monomer + CO2

Initial State Final State

Polymer

• 최적 중합조건 결정 • 중합 후 잔류 단량체 제거

SCFmonomerinitiator

Objectives – 초임계 상거동 자료의 용도 예


C CH

H

CH3

C OOCH2CF3

C CH

H

CH3

C OOCH2CF3

n

- Carbon dioxide (min. 99.99% purity) - Korea industrial Gases

- 2,2,2-trifluoroethyl methacrylate: (TFEMA: min. 99% purity) - Aldrich- poly (2,2,2-trifluoroethyl methacrylate): bulk polymerization

Materials

24hrs

- Initiator ; AIBN [1.0 wt% of monomer]

- Temperature ; 70 ˚C

- Mw ; 268,000 PDI ; 1.6

characterization by GPCWater bath

70’C

Bulk polymerization condition

5.0±


1. Camera

2. Light source

3. Borescope

4. Thermocouple

5. View cell

6. Magnetic stirrer

7. Air bath

8. Digital thermometer

9. Digital pressure transducer

10. Pressure gauge

11. Hand pump

12. Computer monitor

13. Trap

Experimental apparatus – variable volume cell


CO2 + monomer system

CO2

단량체 혹은 고분자주입 후

CO2, N2로 pu gr e

CO2 주입

(실린더 혹은 실린지펌프이용)

일정 온도에서

1-phase 되도록

가압 후 안정화

2-phase 될 때까지천천히 감압

(bubble, dew, mixture critical point)

CO2

Experimental procedure

CO2 + polymer system

압력을 더 내리면 Cloud point (운점) 관측 가능

천천히 감압하면 임계현상보임


Calculation: Peng-Robinson equation of state

∑∑=i

ijjj

imix axxa )1()( ijjjiiij kaaa −=

∑∑=i

ijjj

imix bxxb

2)bb(

b jjiiij

+=

binary parameter

ijk

van der Waals 1-fluid mixing rule

2

∑

−=

N

i

cal

PPP

OBFexp

exp

25.02

22

)]1)(26992.054226.137464.0(1[

/07780.0

/45724.0

r

cc

cc

T

PTRb

PTRa

−−++=

=

=

ωωα

22 2 bbVVa

bVRTP

−+−

−=

αPeng-Robinson EOS

pure parameters

ωTc, Pc,


Calculation: Sanchez-Lacombe lattice-fluid equation of state

0]~)11()~1[ln(~~~2 =−+−++ ρρρr

TP

Tvvv

rTvP

~~1

~11ln~11

~~~

−

−+−=

*~

TTT ≡

kT

** ε=

*~

PPP ≡

ρρ

≡≡ρ

≡∗

*VV

~1v~

*

**

vP ε

=

)( ** rvNV =

or

*** ,, ρPT

rv ,, **εor

pure parameters


Estimation method of pure parameters : TFEMA

Group Contribution method: Method of Wilson and Japerson

Critical constants Tc, Pc, Estimation based Zero, first and second order methods (1996)

K15.380Tb = F-Tech Inc. data

∆+∆+−−=

+−=

+∆+∆+−=

∑∑

∑∑

jj

kkr

cc

2.0

jj

kkrbc

)pcj(M)pck(N041.0N0290403.000922295.0Y

)]Yexp(96601.0/[T0186233.0P

])tcj(M)tck(NN019846.0048271.0/[(TT

H

H

H

C

C

F

F

FC

C CH

H CO

O

H2



0.4773-

29.13barPc

541.12KTc

380.15KTb

TFEMAUnit

ωVapor pressure data 이용하여 S-L parameters구함

: Lee-Kesler method

ω

1/T [K-1]

0.0020 0.0025 0.0030 0.0035 0.0040

ln P

[bar

]

-6

-4

-2

0

2

Peng-Robinson EOSVapor pressure data [F-Tech Inc.]



1510.00

574.50

305.00

CO2

1167.20kg/m3ρ*

294.79MPaP*

711.40KT*

TFEMAUnit

CO2 parameter : Journal of Applied Polymer Science, Vol. 36, 583-597 (1988) T [K]

260 280 300 320 340 360 380 400

P [b

ar]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Vapor pressure data [F-Tech Inc.]S-L EOSP-R EOS


Estimation method of pure parameters : poly (TFEMA)

1510.00

574.50

305.00

CO2

1392.63kg/m3ρ*

441.04MPaP*

600.03KT*

Poly(TFEMA)Unit

C CH

H

CH3

C OOCH2

CF3

n

67.12363.43136.60-46.65-100.69

ρ*

-134.86168.9682.23-29.67-105.41

P*

-54.57-76.3897.41-7.65-18.08

T*

1CF3

1COO1C2CH2

1CH3

nFirst order

)orP,TX(XX)X(f ***0 ρ=−=

1019.47 kg/m3ρ*o

489.46 MPaP*o

666.95 KT*o

valueparameter

Ing. Eng. Chem. Res., Vol. 36, 3968-3973 (1997)


Pressure-composition (P-x) isotherms

Experimental Results


0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

P [M

Pa]

0

2

4

6

8

10

12

14 323.15K333.15K343.15K353.15K

VAPOR + LIQUID

FLUID

T [K]

280 300 320 340 360 380 400 420 440 460

P [M

Pa]

0

20

40

60

80

100

This WorkCO2 vapor pressure

LIQUID + LIQUID

FLUID

+ poly (TFEMA) system: LCST behaviorTemperature-Pressure (T-P) diagram of CO2


Modeling 1 – CO2 + TFEMA system


0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

P [M

Pa]

0

2

4

6

8

10

12

14 323.15K333.15K343.15K353.15K

VAPOR + LIQUID

FLUID


0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

P [M

Pa]

0

2

4

6

8

10

12

14 323.15K333.15K343.15K353.15K

VAPOR + LIQUID

FLUID

Peng-Robinson EOS Sanchez-Lacombe lattice-fluid EOS

kij -0.01260.08470.09330.10100.1159kij

353.15343.15333.15323.15T [K]


T [K]

280 300 320 340 360 380 400 420 440 460

P [M

Pa]

0

20

40

60

80

100This WorkCO2 vapor pressurekij = 0kij = -0.100kij= -0.100 etaij= -0.165

Liquid + Liquid

Fluid

P-T diagram : Sanchez-Lacombe lattice-fluid EOSLower Critical Solution Temperature

Poly (TFEMA) : 3.91wt%

Modeling 3 – CO2 + poly (TFEMA) system


Conclusions

온도 323.15 ~ 353.15K, 압력 20~120 bar 범위에서 CO2 + trifluoroethyl methacrylate 계에 대한 고압 상평형 데이터(P-x diagram)를 variable volume view cell을 이용하여 얻었다.

온도 320 ~ 460 K, 압력 320~600 bar 범위에서 CO2 + poly (trifluoroethyl methacrylate) 계에 관한 임계 거동(LCST critical locus)을 관측하였다.

CO2와 TFEMA, poly (TFEMA)의 상거동에 대하여 pure parameters를 그룹기여방법을 이용하여 얻고 P-R EOS와 S-L EOS로 모델링 하였다. CO2 + trifluoroethyl methacrylate 계의 경우 S-L EOS가 임계점을 높게 예측하는것을 알 수 있었다. CO2 + poly (trifluoroethyl methacrylate) 계는 두개의 binary parameters를 이용하여 모델링 하였다.

앞으로 CO2 + poly (trifluoroethyl methacrylate) + trifluoroethyl methacrylate에 관한ternary phase behavior에 관한 실험 및 모델링을 연구해보고자 한다.

phase behavior and modeling of co + 2,2,2- trifluoroethyl

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