chemical composition and microstructure analysis of ... · 3 chain length end group block length...

1

Chemical Composition and Microstructure Analysis of Complex

Polymers by Multidimensional Liquid Chromatography

Harald Pasch, Khumo Maiko, Pritish Sinha SASOL Chair of Analytical Polymer Science Department of Chemistry and Polymer Science Wolf Hiller, Mathias Hehn Faculty of Chemistry Technical University Dortmund, Germany

2

Stellenbosch – South Africa

Darmstadt

http://en.wikipedia.org/wiki/File:Stellenbosch_from_Papagaaiberg.jpg

3

Chain Length End Group

Block Length Architecture

Molar Mass

Häu

figke

it Chain length

Chemical composition

Functionality Type

Molecular topology

Molecular Heterogeneity of Complex Polymers

SEC

LAC

LCCC

DC

D2C

DC

D2C

DC

D2C

DC* *

D

D

D

D

D

D

D

D

D

D

D

D

D

D

D

D

D D

D

D

HC

H2C

HC

H2C

HC

H2C

HC* *

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H H

H

H

Isotactic

Atactic

Syndiotactic

*

H

H3COOCCH3

H H

H3COOC

CH3

H H

H3COOC

CH3

H

*

*

HH H

H3COOC

CH3

H H

H3C

COOCH3

H

*

H3CCOOCH3

*

HH H

H3C

COOCH3

H H

H3COOC

CH3

H

*

H3CCOOCH3

Isotopic composition H vs. D

4

Liquid Chromatography of Polymers

S S

S

S S

S

SEC

Log

M

Elution volume or Kd

LC-CC LAC Gradient

Pore in stationary phase

Example: column: Nucleosil Si 100 mobile phase: THF / Hexane 80:20 PS PVAc PMMA S injection solvent

5

The LEGO Approach

6

Comprehensive 2D-LC for Maximum Selectivity

7

Functional Polyethylene Oxides

Alk(Ar) OH +O

Alk(Ar) (OCH2CH2)n OH

secondary reactions additional functionality fractions

H (OCH2CH2)n OH

Alk(Ar) (OCH2CH2)n OAlk(Ar)

(OCH2CH2)n

Molar mass distribution Functionality type distribution Amount of cyclics

Washing formulations

Body care Dispersants

Emulsifiers

Paper chemicals

http://us.meadwestvaco.com/AboutUs/Profile/BusinessesandBrands/SpecialtyChemicals/MWV003539

8

Functionality separation by LC-CC Oligomer Separation by LAC stationary phase: RP-18 stationary phase: Si mobile phase: MeOH-water 80:20 mobile phase: i-PrOH-water 88:12


0

20

40

60

80

100

Elution Volume (mL) 1 2 3 4 5 6 7 8

PEG

C10

C12

C13

C14

C15

C16

C18

Nonylphenyl

0

20

40

60

80

100

Elution Volume (mL)

2 3 4 5 6 7 8

Det

ecto

r Sig

nal

16 14 15

11

12 13

8

9

10

6 7

Endgroup selectivity Chain length selectivity

J.-A. Raust, A. Bruell, P. Sinha, W. Hiller, H. Pasch. J. Sep. Sci. 33 (2010) 1-7

CnH2n+1O(CH2CH2O)xH CnH2n+1O(CH2CH2O)xH

9

Degasser

Pump

Degasser

Pump Injector HPLC Column

2D Chromatography HPLC vs. SEC

Detector

Data Processing

Waste

1. Dimension: HPLC/LCCC

2. Dimension: GPC

SEC Column

10

Endgroup and oligomer separation by 2D-LC (LC-CC x LAC)

C10 C9Φ C12 C13 C14 C15 C16 C18

Endgroup Length

Oligom

er Length

4-8 9 10 11 12 13

14

15

16


C16H31O(CH2CH2O)14H

J.-A. Raust, A. Bruell, P. Sinha, W. Hiller, H. Pasch. J. Sep. Sci. 33 (2010) 1-7

11


Quantification of oligomer distributions and topology of endgroups by 2D-LC (LC-CC x LAC) – 1H-NMR

LC-CC– 1H-NMR for topology of endgroups LAC– 1H-NMR for oligomer distributions

W. Hiller, M. Hehn, P. Sinha, J. Raust, H. Pasch. Macromolecules 45 (2012) 7740-7748

12


Quantification of oligomer distributions and topology of endgroups by 2D-LC (LC-CC x LAC) – 1H-NMR

W. Hiller, M. Hehn, P. Sinha, J. Raust, H. Pasch. Macromolecules 45 (2012) 7740-7748

13

Separation According to Isotope Effects and Microstructure

14

Separation of PS by Degree of Deuteration

45 oC

41 oC 54 oC

d-PS d-PS

d-PS

h-PS h-PS

h-PS

LCCC LCCC

LAC

LAC

SEC

stationary phase:

Nucleosil C18 300 Å

mobile phase:

THF-ACN 47:53 v/v

SEC Kd = exp (∆S/R - ∆H/RT)

VR = Vi + V Kd

P. Sinha, G. Harding, K. Maiko, H. Pasch, J. Chromatogr. A 1265 (2012) 95-104

15

Separation of PS by Degree of Deuteration

Separation of similar molar masses and chemical structures the only difference being the deuteration

P. Sinha, G. Harding, K. Maiko, H. Pasch, J. Chromatogr. A 1265 (2012) 95-104

LC x LC: injection volume: 50µL 1st Dimension conditions: Hypercarb (150mmx4.6mm), 30°C; Flow rate: 0.044 mL/min (387 min); mobile phase: DCM/acetone gradient 2nd Dimension conditions: PL Mixed E (300mmx7.5mm); 25°C; loops :200µL; Flow rate: 2mL/min (4.5min); Detection: ELSD

0 1 2 3 4 5 6 7 8 9

0.00

0.01

0.02

0.03

0.04

0.05

0.06

ELS

D R

esp

onse

Elution volume (ml)

Vertical cut of 2D (SGIC)Syndio 4900 (S3)

Iso 4890 (I1)

0 1 2 3 4 5 6 7 8 9

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Iso 4890 (I1)

ELS

D R

espo

nse

Elution volume (ml)

Horizontal cut of 2D (SEC)Syndio 4900 (S3)

0 2 4 6 8

0.00

0.02

0.04

0.06

0.08

0.10

0.12

ELS

D R

espo

nse

Elution volume (ml)

Vertical cut of 2D (SGIC)Syndio 4900 (S3)

Syndio 60150 (HS4)

0 2 4 6 8

0.00

0.02

0.04

0.06

0.08

0.10

0.12

ELS

D R

espo

nse

Elution volume (ml)

Horizontal cut of 2D (SEC)

Syndio 60150 (HS4)

Syndio 4900 (S3)

Microstructure Analysis of PMMA

K. Maiko, M. Hehn, W. Hiller, H. Pasch, Anal. Chem. 85 (2013) 9793-9798

2 4 6 8 10-0.002

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

0.018

0.020

ELSD

Sig

nal

SGIC Elution volume (ml)

2 4 6 8-0.002

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

0.018

ELSD

Sig

nal

SEC Elution volume (ml)

Microstructure Analysis of PMMA

K. Maiko, M. Hehn, W. Hiller, H. Pasch, Anal. Chem. 85 (2013) 9793-9798

18

Hyphenation of Selective Separations with Spectroscopic Methods

19

On-flow-Coupling of HPLC and 1H-NMR

Loop collector

Waste

HPLC System

NMR Console AVANCE 400

Magnet

Pump

Sampler

Detector

On-Flow

400 MHz

AGILENT 1100

5mm NMR tube

rf coils

rf coils

Flow cell

20

HPLC-NMR Coupling: Experimental Challenges

Use of protonated solvents: overlapping of polymer and solvent signals Efficient solvent suppression techniques !

Use of HPLC quality solvents: Solvent impurities cause strong signals Solvents with NMR purity !

styrene-ethylacrylate copolymer

Solvent mixture THF-ACN

21

Microstructure Analysis of Polyisoprene

R1 CH2 C R2

CH3

HC CH2

n

C CH

CH3

CH2 R2CH2R1n

R1 CH2 CH R2

C CH3

CH2

n

1,2-PI

1,4-PI

3,4-PI LCCC of 1,4-PI

mobile phase: butanone/cyclohexane ■ 70:30, ● 92:8, ▲97:3 stationary phase: 3 x C18 (100-5, 300-5, 1000-7)

W. Hiller, P. Sinha, M. Hehn, H. Pasch, T. Hofe. Macromolecules 44 (2011) 1311-1318

22

Microstructure Analysis of Polyisoprene: LCCC-NMR

On-flow LCCC-NMR of blend of 1,4-PI (20.7 kg/mol) and 3,4-PI (72.8 kg/mol) at critical conditions of 1,4-PI, 100 µL injection, flow rate 0.5 mL/min

Normalized NMR intensities and chemical composition distributions of 1,2-, 1,4- and 3,4-isoprene units

W. Hiller, P. Sinha, M. Hehn, H. Pasch, T. Hofe. Macromolecules 44 (2011) 1311-1318

23

Microstructure Analysis of PI-PMMA Block Copolymers

W. Hiller, H. Pasch, P. Sinha, T. Wagner, J. Thiel, M. Wagner, K. Müllen Macromolecules 43 (2010) 4853-4863

.

LCCC for PI stationary phase: Nucleosil C18 300-5 + 1000-7

mobile phase: 1,4-dioxane

LCCC for PMMA stationary phase: Nucleosil Si 300-5 + Si 1000-7

mobile phase: ethyl acetate

In both cases single mobile phases, adjustment of critical conditions through temperature variations

24



Separation of PMMA-PI blends at critical conditions for PMMA (left) and PI (right)

PMMA (Mp=22700)

PMMA (Mp=22700) 1,4-PI (Mp=20500)

1,4-PI (Mp=95000)

25



Separation of 3,4-PI-PMMA copolymer (52 kg/mol)

at critical conditions for PMMA (left) and PI (right)

PI Homopolymer

Copolymer

26



Chemical composition analysis of 3,4-PI-PMMA copolymer (52 kg/mol) at critical conditions for

PMMA (left) and PI (right)

PI Homopolymer Copolymer

27

MS as a Detector for Liquid Chromatography

28

Aliphatic Polyesters: Background

Paint/Coatings

Polymer/Binder

Pigments

Additives

Multi-vesiculated polyester particles

Main constituents of UPR: Maleic anhydride Phthalic anhydride Propylene glycol

29

Aliphatic Polyesters: Chemistry

Simple monomer structures… … but complex rearrangements during polymerization



Molar Mass

Häu

figke

it

Chain Length Functional Groups

30

Aliphatic Polyesters: Molar Mass Analysis by SEC

Size exclusion chromatography

Fraction 2

Fraction 3

Fraction 4

Fraction 5

Fraction 6

Fraction 7

Fraction 8

n = 7

n = 6

n = 5

n = 4

n = 3

n = 2

31

MALDI-TOF analysis of SEC fractions

Aliphatic Polyesters: End Group Analysis by SEC-MALDI

Chemical structure Abbreviation m/z(exp) values for n

2 3 4

A.

HO-[PA-PG]n-PA 602 808 1014

B.

HO-[PA-PG]n-H 453 660 866

C.

PG-[PA-PG]n-H 512 718 924

D.

cyclic of

[PA-PG]n

434 640 847

E.

cyclic of

PG-[PA-PG]n

492 698 904

32

Aliphatic Polyesters: End Group Analysis by HPLC

12 16 20 24 2812 16 20 24 280.0

0.2

0.4

0.6

0.8

1.0

12 16 20 24 28Elution volume (ml)

s28

% THF

5 7

5

64

4

3

3

3

2

2

1

1

2

Norm

alize

d EL

SD s

igna

l

Elution volume (ml)

s23

Elution volume (ml)

s25

40

50

60

70

80

90

100

1

14 16 18 20 22 24 260.0

0.2

0.4

0.6

0.8

1.0

7

6

5

4

3

2

Nor

mal

ized

ELS

D s

igna

l

Elution volume (ml)

zoomedin

1

peak splitting 20 21 22 23 24 25 26

0.00

0.05

0.10

0.15

10

8

9

Analysis conditions: Stationary phase: SupelcoCN 100Å, 5μm, Mobile phase: THF/Hexane, Temp: 30⁰C, Flow rate: 1.00 mL/min, Detector: ELSD, Injection vol: 20 μL

Solvent Gradient HPLC

Significantly improved separation Oligomer/functional group formation as a function of polymerization time

33

Aliphatic Polyesters: HPLC Fractionation and MALDI-ToF

0

20

40

60

80

100 %Int.

1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 Mass/Charge

1954.39

1541.56 1970.76 2160.48

1557.86

1896.09 2177.40

1912.54 1690.31 2012.97

1499.87

2102.30 2218.61

1747.73

1615.83

1763.96

1295.39 2367.04 1927.62

1521.57 1294.00

1714.15 1839.83 1465.91

CNa

CNa

CNa

CNa CK

CK CK CK

BNa

BNa

BNa

BK

BK CNa

BK

BK fraction 9

fraction 10

BNa

m/z

0

20

40

60

80

100

%Int.

600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

Mass/Charge

718.05

659.96

924.39

641.04

866.29

681.78

1130.86

1072.89907.36

866.73

940.95

1954.39

1541.56

1088.90

1970.76 2160.481557.861896.09

1072.80

2177.401912.54

1335.03

1690.311351.30

1499.87

2218.61

1747.73

1763.96

1483.871295.39

1277.66

2367.04

1521.57

1839.83 2070.86

fraction 5

fraction 6

fraction 7

fraction 8

fraction 9

fraction 10

CNa

CNa

CNa

CNa

CNa

CK

CK CKCK

CNaCNa

BNa

BNa

BNa

BNaBNa

BNa

BK

CNa

CK

m/z

BK

BK

BK

B. HO-[PA-PG]n-H/Na+ : m/z 866 (n=4); 1896 (n=9)

C. PG-[PA-PG]n-H/Na+ : m/z 718 (n=3); 2160 (n=10)

MALDI-ToF spectra of fractions 5 to 11 collected from the gradient elution HPLC separation of sample s28 from PA-PG batch.

OCH

CH3

CH2HO

G: PG-PG-[PA-PG]n-H/Na+: m/z 1615 (n=7) ; m/z 2218 (n=10)

Zoomed-in MALDI-ToF MS spectra of fractions 9 to 11 to indicate the presence of an additional oligomeric structure.

58 Da

Fraction 9

Fraction 10

Fraction 11

34

Aliphatic Polyesters: Comprehensive 2D-LC

To Waste

LC-CC or

Gradient-HPLC

Quaternary Pump, Degasser HPLC system

Binary Pump, Degasser HPLC system

SEC

ELSD

UV Detector

Oligomer length and endgroups

1st dimension: solvent gradient HPLC 2nd dimension: SEC

35

Aliphatic Polyesters: SEC-SFC-ESI-QToF

ELSD

PDA

Column

Sample manager

Solvent manager Size exclusion chromatography

Supercritical fluid chromatography

Analysis conditions: Stationary phase: Acquity UPC2 BEH Mobile phase: CO2 (A) and 1% formic acid in ACN (B). Temp: 30°C, Pressure:150bar.

SFC of SEC fraction 2



SFC of s28

36

Aliphatic Polyesters: ESI-QToF Analysis of SFC Fractions

37

Annual production of polyolefins

> 100 million tons

Fractionation of polyolefins does not work at ambient temperatures



Molar Mass

Häu

figke

it

Chain length (MMD)

Chemical composition (CCD)

ABBBAAAABB

BBBBBAABAA

AAAAABBBBB

Molecular topology (MTD) Long Chain Branching Short Chain Branching

LDPE

LLDPE

HDPE

CRYSTAF

TREF

38

EVAc Copolymers

0 5 10 15 20

0

2

4

6

8

10

12

0

20

40

60

80

100

Dete

ktor

signa

l ELS

D [V

]

Elutionsvolumen [ml]

EVA 5% VA EVA 12% VA EVA 14% VA EVA 19% VA EVA 28% VA EVA 45% VA EVA 50% VA EVA 60% VA EVA 70% VA PVAc-St. 164KD PVAc-St. 32KD PE-St. 126KD

% C

yclo

hexa

non

PVAc PE

PP by Tacticity

0 5 10 15 20 25

0,0

0,2

0,4

0,6

0,8

1,0

isotactic PP

linear PE

syndio-tactic PP

responseof ELSD[Volts]

elution time [minutes]

atactic PP

Start of gradient

Polyolefin Separation by Composition or Microstructure

stationary phase: silica gel mobile phase: gradient of decaline-cyclohexanone

stationary phase: Hypercarb mobile phase: gradient of 1-decanol to TCB

T. Macko, H. Pasch. Macromolecules 42 (2009) 6063-6067 A. Albrecht, R. Brüll, T. Macko, H. Pasch. Macromolecules 40 (2007) 5545

39

The LEGO Approach for Polyolefins: HT-SEC-FTIR-DSC

Stage: 160°C

Nebulizer 150°C

Vacuum line

Hper DSC

S. Cheruthazhekatt, T.F.J. Pijpers, G.W. Harding, V.B.F. Mathot, H. Pasch. Macromolecules 45 (2012) 2025−2034

HT-SEC

TREF Fractionation of IPC

30 40 50 60 70 80 90 100 110 120 1300

10

20

30

40

50

60

Wi% Wi%/∆T

Wi%

TREF elution temperature (ºC)

0

10

20

30

40

50

EP Rubber

iPP

Segmented EPC

Controlled cooling

(1 °C/h)

1. Slow crystallization

Dissolved polymer +

support

Most crystalline, More crystalline

Less crystalline, Least crystalline

2. Elution

Increasing temperature

T1 T2 T3 T4 T5

Fractionation according to crystallizability

IPC: complex mixture of various (E/P) components - amorphous EP rubber - semi-crystalline EPC ?????? - crystalline iPP - aPP + hPE ??????

41

Impact PP Copolymers (IPC); TREF Fraction at 80 oC


complex mixture (1) amorphous EP rubber, (2) semi-crystalline EPC, (3) crystalline iPP, (4) aPP, (5) hPE

42


0 1 2 3 4 5 6 7 80.00

0.01

0.02

0.03

0.04

3V 80

ELSD

Res

pons

e (V)

Elution volume (mL)

Star

t of g

radi

ent

Ethy

lene

rich

EPC

an

d PE

EPC

iPP

HT-HPLC stationary phase: Hypercarb

Mobile phase: gradient 1-decanol/TCB

HT-2D-LC 1st dimension: HT-HPLC

2nd dimension: HT-SEC in TCB


43 43

20 40 60 80 100 120 140 160 180

-2.4

-1.6

-0.8

0.0

0.8

1.6

Heat

Flo

w (W

/g)

Temperature (°C)

2nd Heating 1st Cooling

3V A - 130

115.8 °C

110.9 °C

164.0 °C

123.9 °C

0.0

0.1

0.2

0.0

0.1

0.2

0.3

0.0

0.2

0.4

0.6

1000 1500 2000 2500 3000

Linked spectrum at Elution volume 6.3 mL



Wavenumbers (cm-1)

Abso

rban

ce

3V A - 130


44

Limitations of SEC/HPLC

Problems of SEC:

Limited towards higher molar masses

Shear degradation (mechanical stress due to stationary phase

Separation of linear and branched molecules

Adsorption on the stationary phase

Field Flow Fractionation

45

Coupling of FFF and 1H-NMR

Temperature Field

46

ThFFF-NMR of PI, PS and PMMA

Universal calibration

ThFFF SEC

Same molar masses but different elution volumes

for PI and PS/PMMA

W. Hiller, W. van Aswegen, M. Hehn, H. Pasch, Macromolecules 46 (2013) 2544-2552

47

ThFFF-NMR of Block Copolymers

Uniform chemical composition as a function of molar mass

Clear indication for fractions of different chemical compositions

W. Hiller, W. van Aswegen, M. Hehn, H. Pasch, Macromolecules 46 (2013) 2544-2552

48

ThFFF of Block Copolymers

selective towards chemical composition

N

Ph PhH

OOy zx

Separation according to block copolymer composition based on differences in DT

Block DT (cm2/s.K) polybutadiene 0.25 x 10-7

Poly(2-vinyl pyridine)

Still to be determined

Poly (tert-butyl methacrylate)

1.074 x 10-7

B830V180T1350 255 800 g/mol

RM

S R

adiu

s (n

m)

Mol

ar M

ass

(g/m

ol)

?

size

W. van Aswegen, W. Hiller, M. Hehn, H. Pasch, Macromol. Rapid Commun. 34 (2013) 1098-1103

Summary

Interaction LC is a perfect tool for the chemical composition and microstructure analysis of complex polymers

Comprehensive 2D-LC provides maximum selectivity regarding chemical composition/microstructure/molar mass separation

On-flow LC-1H-NMR provides microstructure as a function of molar mass or chemical composition

High-temp multidimensional LC has become a feasible tool for polyolefin analysis

If LC does not work – use field-flow fractionation

Vr

1

2

1

2

50

Multidimensional HPLC of Polymers Springer International Publishing Switzerland, 2013

Authors: Harald Pasch, Bernd Trathnigg ISBN: 978-3-642-36079-4 (Print) 978-3-642-36080-0 (Online)

http://link.springer.com/search?facet-author=%22Harald+Pasch%22



http://link.springer.com/search?facet-author=%22Bernd+Trathnigg%22

http://link.springer.com/search?facet-author=%22Bernd+Trathnigg%22

Thank you for your attention

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chemical composition and microstructure analysis of ... · 3 chain length end group block length...

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