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© Fraunhofer LBF
APPLICATION OF SEC IN TWO-DIMENSIONAL LIQUID CHROMATOGRAPHY OF POLYOLEFINS
T. Macko, S.S. Bhati, R. Brüll Fraunhofer-Institute for Structural Durability and System Reliability LBF,
Darmstadt, Germany
© Fraunhofer LBF
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© Fraunhofer LBF
HT-
HPL
C li
ght
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Fraunhofer Institute, Darmstadt, Germany, Division Plastics, Group of Material Analytics
© Fraunhofer LBF
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World-wide production of polyolefins
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Challenges in Polyolefin Analysis
Multidimensional techniques are required to analyze the chemical heterogeneity
• Chemical composition distribution (CCD) • Molecular weight distribution (MWD) • Stereochemical distribution • Comonomer sequence length distribution • Long chain branch distribution (LCB)
MWD CCD
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High-temperature chromatograph from PolymerChar
OVEN for columns
Gradient and
isocratic PUMP
IR Detector OVEN for valves
ELS-Detector AUTOSAMPLER
Solvent selector with 8
solvents
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High-temperature chromatographic instrument
Method selector, solvent selector, column selector and pump selector valves enable to realize:
Method selector
Column selector
Solvent selectors
solvent gradient (SGLC), temperature gradient (TGIC), critical (LCCC), size exclusion (SEC), two-dimensional liquid chromatography (2D-LC) measurements
multimethods, multipurpose = universal liquid chromatograph for chromatographic analysis of polyolefins
IR ELSDWasteWaste Waste
Gradient pump
Isocratic pump
Autosampler
Columnselector
SECcolumn for 2D-LC
Solventselector A
Solventselector B
Samplesolventvalve
SECcolumn HPLC
columns
Valve with filter
Injection valve
MethodselectorInjection
valve for 2D-LC
Pump selector
Pump selector
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© Fraunhofer LBF
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Separation of EB copolymers and PE (bimodal HDPE )
Bimodal polyethylene
0 2 4 6 8 10 12 140
1
2
3
4
5
6
7
8
EB77
EB65
EB56 EB35
EB19
ELSD
resp
onse
[V]
(Pea
k ar
ea n
orm
aliz
ed)
Elution volume [mL]
G-10 min
b)
EB5 EB11
PE126
0
20
40
60
80
100
Con
tent
of T
CB
[vol
. %]
8 9 10 11 12 13 140123456789
10
ELS
D re
spon
se [V
](P
eak
area
nor
mal
ized
)
Elution volume [mL]
PE2 PE16.5 PE36.5 PE60 PE118 PE181 PE260
a)0
20
40
60
80
TCB
con
tent
[vol
. %]
linear PE standards
Mobile phase: 1-decanolTCB
Column: Hypercarb 100x4.6 mm
Temperature: 160 °C
Detector: ELSD
PE 2 kg/mol
ethylene/butene copolymers
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Comparison of SEC chromatograms from HT 2D-LC
0.000
0.002
0.004
0.006
0.008
0.010
150149148
148 149 150
b)ELSD
resp
onse
[V]
BiHDPE
Number of fractions
a)0.000
0.002
0.004
0.006
0.008
0.010 BiHDPE
IR re
spon
se [V
]IR-detector
ELS-detector
K.N. Prabhu, R. Brüll, T. Macko, K. Remerie, J. Tacx, P. Garg, A. Ginzburg, J. Chromatogr. A, 2015, 1419, 67.
Solvent peak
Polymer peak
Injection signal
Polymer peak
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0.000.010.020.030.040.05
IR re
spon
se [V
]
BiHDPE
Number of fractions
0.0000.0010.0020.0030.0040.005
150149148
150149148a)
b)
BiHDPE
ELSD
resp
onse
[V]
Comparison of SEC chromatograms from HT 2D-LC
IR-detector
ELS-detector
K.N. Prabhu, R. Brüll, T. Macko, K. Remerie, J. Tacx, P. Garg, A. Ginzburg, J. Chromatogr. A, 2015, 1419, 67.
Solvent peak
Polymer peak
Injection signal
Polymer peak
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Experimental parameters used for HT 2D-LC
Experimental parameters
HT 2D-LC method
I II III IV V
Transfer loop volume [μL] 200 100 50 100 100
Flow rate in HPLC column [mL/min] 0.2 0.1 0.05 0.02 0.01
Flow rate in SEC column [mL/min] 2.5 2.5 2.5 1.5 1.5
Length of the SEC column [mm] 150 150 150 300 300
Time between injections into SEC column [min] 1 1 1 5 10
Total number of HPLC fractions [No. of SEC analysis] 100 200 400 200 200
Total volume of the solvent gradient [mL] 10 10 10 10 10
Number of fractions in the gradient 50 100 200 100 100
Time of complete HT 2D-LC analysis [min] 100 200 400 1000 2000
ELS-detector IR-detector
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Contour plots of BiHDPE obtained from HT 2D-LC
IR-detector ELS-detector
Polyethylene pipes
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High Temperature 2D-LC of bimodal HDPE (HPLC SEC): 2D-plot – chemical composition distribution and molar mass distribution visible
Column: Hypercarb. Mobile phase: 1-decanolTCB. Temperature: 160°C. K.N. Prabhu, R. Brüll, T. Macko, K. Remerie, J. Tacx, P. Garg, A. Ginzburg, J. Chromatogr. A, 2015, 1419, 67.
Bimodal polyethylene
HDPE LLDPE
Low molar mass PE (incl. oligomers)
Both axis in the contour plot are calibrated
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Liquid chromatography under critical conditions of iPP
Column: Hypercarb. Critical mobile phases: 2-octanol/TCB, 87/13 vol. Temperature: 160°C.
S.S. Bhati, T. Macko, D. Mekap, R. Brüll, Macromol. Chem. Phys., 2015, 216, 2179.
Critical conditions
1.0 1.5 2.0 2.5 3.0 3.50.000
0.004
0.008
0.012
0.016 iPP1.2
iPP8.6
iPP52.3
iPP136.5
iPP348.3
ELSD
resp
onse
[V]
Elution volume [mL]a) 2.9 3.0 3.1 3.2 3.30.000
0.004
0.008
0.012
0.016 iPP1.2
iPP8.6
iPP52.3
iPP136.5
iPP348.3
b)
ELSD
resp
onse
[V]
Elution volume [mL]2.9 3.0 3.1 3.2 3.3
0.000
0.004
0.008
0.012
0.016 iPP1.2
iPP8.6
iPP52.3
iPP136.5
iPP348.3
c)
ELSD
resp
onse
[V]
Elution volume [mL]
SEC Adsorption LC
Elution volume = constant
Elution volume = increases with MM
Elution volume = decreases with MM
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Separation of high impact PP with high temperature 2D-LC (LCCC of iPP + SEC) with IR-detection
S.S. Bhati, T. Macko, D. Mekap, R. Brüll, Macromol. Chem. Phys., 2015, 216, 2179.
Amorphous ethylene-propylene copolymers
Column packing: Hypercarb. Mobile phase: 2-octanol/ODCB, 83/17 vol. (constant composition) Temperature: 160 °C.
iPP
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Separation of PP-g-MA
Contour plot (HPLC-SEC) obtained with IR-detector. HT SEC calibrated with PS-standards.
Chromatograms of PP-g-MA. Column packing: Silica gel. Mobile phase: Gradient Decalin Cyclohexanone. Temperature: 160 °C.
K.N. Prabhu, T. Macko, R. Brüll, K. Remerie, J. Tacx, P. Garg, A. Ginzburg, J. Chromatogr. A, 2016, 1441, 96.
iPP
PP-g-MA
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Contour plot for EP copolymer
Only the polymer peaks are selected and plotted as a contour plot.
Contour plot for EP copolymer (59.7 wt. % ethylene)
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Calibrations of IR-response (concentration of polymer), SEC (MMD) and HPLC separation (CCD)
CCD
MMD
Concentration of polymer
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Differences in the contour plots = differences in MMD and CCD Matrix approach
The first EP sample The second EP sample
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Contour plot = matrix
One contour plot chosen as reference
Subtraction of matrices
unique segments in samples
Addition and subtraction of matrices
identical segments in samples
Results = MMD and CCD presented in
the contour plots
Matrix approach
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Polymer sample EP59.7 EP39.8
Segments Identical Unique Identical Unique
Mass fraction
[wt. %] 10.5 89.5 10.5 89.5
Average M [kg/mol] Mn Mw Mn Mw Mn Mw Mn Mw
79.6 112.6 107.1 141.7 79.6 112.6 107.6 147.5
Average EC [wt. %] ECn ECw ECn ECw ECn ECw ECn ECw
44.32 44.45 59.6 59.92 44.32 44.45 36.08 36.89
Average MM and CD of unique segments and indentical segments in the compared copolymer samples
S.S. Bhati, T. Macko, R. Brüll, Polyolefins J, 2016, in print.
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Unique segments of two copolymers Both the
copolymers contains 89 wt. % unique segments
S.S. Bhati, T. Macko, R. Brüll, Polyolefins J, 2016, in print.
MMD CCD
MMD CCD
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Identical segments of two copolymers Both the copolymers had
10 wt. % identical segments
CCD
CCD
MMD
MMD
S.S. Bhati, T. Macko, R. Brüll, Polyolefins J, 2016, in print.
© Fraunhofer LBF
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HPL
C li
ght
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Acknowledgement Prof. R. Alamo (Uni of Florida) Prof. V. Busico (Uni of Naples) Dr. I. Suarez, Dr. B. Coto, (Uni of Madrid) Dr. Ch. Boisson, Dr. O. Boyron, Dr. V. Monteil (Uni of Lyon) Prof. M. Terano, Prof. T. Tanaike (JAIST) Prof. J.B.P. Soares, (Uni of Waterloo) Dr. C. Descours, F. Karbach, Dr. R. Duchateau (Uni of Eindhoven) Dr. T. Poltimäe, Prof. A. Krumme (Uni of Tallinn) Dr. D. Mekap, Dr. R. Cong, Dr. Z. Zhou, Dr. W. deGroot (Dow) Dr. S. Losio (Uni of Milano) Dr. I. Mingozzi, Dr. V. Dolle (LyondellBasell) Prof. W.H. Sun (Chinese Academy of Sciences) Dr. G. van Doremaele, Dr. R. Bernardo (Lanxess) Dr. L. Pereira, Dr. H. Ritchie (Thermo Fisher Scientific) Dr. A. Ginzburg, Dr. J. Tacx, Dr. K. Remerie, Dr. P. Garg (SABIC) Dr. B. Monrabal, J. Sancho-Tello, Dr. A. Ortin, P. de Hierro (PolymerChar) Dr. R. Chitta (DSM Resolve) Dr. S. O‘Donohue, J. Yakhoul, R. Linz (Agilent)
This research forms part of the research programme of the Dutch Polymer Institute (DPI), project #750.
Dr. K.N. Prabhu, Dr. D. Mekap, Dr. J.-H. Arndt, (Fraunhofer Institute LBF)
© Fraunhofer LBF
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Fraunhofer Institute, Division Plastics,
Group of Material Analytics Darmstadt, Germany
High Selective Liquid Chromatography Separations
of Polyolefins
Thank you for your attention!