branching analysis of star polymers by sec event/201… · < 1.0) star polymer ( 0.1 < α...
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Branching Analysis of Star Polymers by SEC
Artjom Döring Martin Schneider Agnes Wycisk Dirk Kuckling
International Symposium on GPC/SEC and Related Techniques Frankfurt, 2014
log
(intri
nsic
vis
cosi
ty)
log (molar mass)
hard sphere (α = 0)
linear coil ( 0.6 < α < 1.0)
star polymer ( 0.1 < α < 0.6)
2
Paderborn
• founded in 1972 • currently more than 20.000 students • material science profile in chemistry, physics and
mechanical engineering
University of Paderborn:
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Research Interests of Prof. Kucklings Working Group:
Smart Polymers
Controlled Radical Polymerization
(NMRP, ATRP, RAFT)
Smart block copolymers for micro heterogeneous organocatalysis
or pigment stabilization
X Y + Z
Smart nanohydrogels for targeted transport and
controlled release systems
Smart and biodegradable block copolymers for
triggered release systems
enzyme
Free Radical Polymerization and photo cross-linking /
photo patterning
Hydrogels for applications in biomedicine and as actuators and sensors in micro-system
technology
Receptor/Ligand modified (hydro)gels for sensor
applications
Multisensitive phase separated hydrogel layers
- NMR - IR &
UV/VIS - SEC
- MS (MALDI, ESI-IMS) - SPR
Analytics
4
core-shell type nanoparticle
hydrophilic shell hydrophobic core
Induced Morphology Change in Star-Shaped Temperature-Responsive Block Copolymers:
unimolecular colloidal nanoparticles: - small dimension (< 20 nm) - spherical morphology
hydrophilic block
temperature-responsive block (LCST) T > Tc
T < Tc
Characterization of the obtained star (co)polymers:
- mean copolymer composition: 1H-NMR
- molecular weight: 1H-NMR, ESI-IMS-MS
SEC (THF, CHCl3, DMAc, HFIP)
- number of arms: viscosity (Kuhn-Mark-Houwink Plot)
5
SEC Setup for Branching Analysis
eluent: N,N-dimethylacetamide (DMAc)
flow: 1 ml/min
injector: manuel injection valve (100 µl, Knauer)
columns: PSS-GRAM (104 Å, 103 Å, 102 Å)
column temp.: 50 ºC (Shimadzu CTO 6A)
detectors: Merck-Hitachi L3000 PDA
Waters RI 2410
PSS ETA 2010 viscosity detector
PSS SLD 7000 MALLS detector
6
Synthesis of Star Polymers
Cl
O NH n
O
Om
multifunctional initiator
O
OO O
OR
OR
OR
OR
Penta-Cl4: R =
H, X =
ClPenta-Br
4: R
= CH3
, X = Br
X
X
X
X
OO
Cl
O
O O
O7
OCl
O
Cl
21-Cl-β-CD
ATRP
Br
n
O
Om
Sample
Initiator
ATRP catalyst
Mn,GPC
[g/mol] D
PS 4-arm Penta-Br4 Cu(I)Br / Me6Tren 40.300 1.26
PNIPAAm 4-arm Penta-Cl4 Cu(I)Cl / Me6Tren 70.000 1.13
PNIPAAm 7-arm 7-Cl-β-CD Cu(I)Cl / Me6Tren 149.800 1.11
PNIPAAm 14-arm 14-Cl-β-CD Cu(I)Cl / Me6Tren 155.000 1.17
PNIPAAm 21-arm 21-Cl-β-CD Cu(I)Cl / Me6Tren
250.000 1.25
7
log
(intri
nsic
visco
sity)
log (molar mass)
hard sphere (α = 0)
linear coil ( 0.6 < α < 1.0)
star polymer ( 0.1 < α < 0.6)
Branching Analysis of Star Polymers
2
2*3ffg −
=
[ ][ ]linear
branchedgη
η='
5.0with)'( /1 == εεgg
[ ]
=
→→ c
spez
Gc
ηη lim
00
B. H. Zimm, W. H. Stockmayer, Journal of Chemical Physics 1949, 17, 1301-1314 B. H. Zimm, R. W. Kilb, Journal of Polymer Science 1959, 37, 19-42
- standard calibration - viscosity detector (universal calibration) - MALLS detector (absolute method) refractive index increment dn/dc is
required
Kuhn-Mark-Houwink Plot
8
Refractive Index Increments in N,N-Dimethylacetamide
Sample Origin dn/dc Poly(styrene) PSS Standard 0.15430±0.0022 Poly(styrene) Synthesized by FRP 0.15520±0.0024 Poly(methylmethacrylat) PSS Standard 0.05829±0.0021 Poly(methylmethacrylat) Synthesized by FRP 0.05737±0.0006 Poly(N-isopropylacrylamide) Synthesized by ATRP 0.06497±0.0013 Poly(N-isopropylacrylamide) 14-arm star polymer Synthesized by ATRP 0.06330±0.0041
dn/dc-measurements of linear and star polymers in DMAc were performed with a refractometer Model 2010/540 (PSS, Mainz)
9
Branching Analysis of Poly(styrene) Star Polymers
Sample Origin Mn [g/mol] PD Poly(styrene) broad, linear PSS 144.000 2.03 Poly(styrene) 3-arm star polymer PSS 265.000 1.14 Poly(styrene) 4-arm star polymer Synthesized by ATRP 40.300 1.26 Poly(styrene) 8-arm star polymer PSS 216.000 1.07
Sample Origin Mn [g/mol] PD Poly(styrene) broad, linear PSS 140.000 2.23 Poly(styrene) 3-arm star polymer PSS 288.000 1.06 Poly(styrene) 8-arm star polymer PSS 220.000 1.06
Sample data provided by PSS
SEC results (universal calibration)
10
24 26 28 300,000
0,002
0,004
0,006
0,008
[η] sp
ez
Elution volume
1,2
1,4
1,6
1,8
log
[η] in
tr(fitt
ed)
Branching Analysis of Poly(styrene) Star Polymers 4-Arm PS star polymer (Aw 152)
20 21 22 23 24 250,000
0,002
0,004
0,006
0,008
0,010
0,012
0,014
Elution volume
[η] sp
ez
0,6
0,9
1,2
1,5
1,8
2,1
2,4
2,7
log
[η] in
tr(fitt
ed)
21 22 23 24 25 260,000
0,002
0,004
0,006
Elution volume
[η] sp
ez
0,6
0,9
1,2
1,5
1,8
2,1
2,4
log
[η] in
tr(fitt
ed)
3-Arm PS star polymer (PSS)
8-Arm PS star polymer (PSS) Results: - ηspez (elution volume) - [η] (elution volume); not always linear - Molar mass (elution volumen) from universal calibration
11
Sample Average number of
arms f Poly(styrene) 3-arm star polymer 2.8 Poly(styrene) 4-arm star polymer 4.0 Poly(styrene) 8-arm star polymer 8.0
Branching Analysis of Poly(styrene) Star Polymers [η] (elution volume) Molar mass (elution volume)
4,4 4,6 4,8 5,0 5,2 5,4 5,6 5,8
1,4
1,6
1,8
2,0
2,2
2,4 Linear Poly(styrene) I (PSS) Linear Poly(styrene) II 3-Arm star PS star polymer (PSS) 4-Arm star PS star polymer 8-Arm star PS star polymer (PSS)
log
[η]
log M
Kuhn-Mark-Houwink Plot [η] (molar mass)
Ve = const
5,2 5,4 5,6
2,0
2,2
2,4
2,6 Broad linear Poly(styrene) y = - 2,48639 + 0,85068 x3-Arm Poly(styrene) star polymer(PSS Mainz)y = - 0,26797 + 0,44200 xCalculated number of armsf = 2,88-Arm Poly(styrene) star polymer(PSS Mainz)y = - 1,02749 + 0,15266 xCalculated number of armsf = 8,0
log
[η]
log M
[ ][ ]linear
branchedgη
η=' ε/1)'(gg = 2
2*3ffg −
=
12
4,4 4,6 4,8 5,0 5,2 5,4 5,6 5,8
1,4
1,6
1,8
2,0
2,2
2,4 PS I PS II 3-arm exp 3-arm theo 4-arm exp 4-arm theo 8-arm exp 8-arm theolo
g [η
]
log M
Branching Analysis of Poly(styrene) Star Polymers
4,5 5,0 5,52
4
6
8
10 3-Arm Poly(styrene) star polymer 4-Arm Poly(styrene) star polymer 8-Arm Poly(styrene) star polymer
f 1
log M
number of arms f increases together with molar mass Synthesis mechanism offers no convienient explanation
slope of the KMH plot lines is too small to provide a constant ratio for g‘:
[ ][ ]linear
branchedgη
η='
13
Branching Analysis of Poly(N-isopropylacrylamide) Star Polymers 4-Arm Poly(NIPAAm) star polymer (MS 344-4) 7-Arm Poly(NIPAAm) star polymer (Aw 312)
14-Arm Poly(NIPAAm) star polymer (Aw 234)
22 23 24 25 26 27 280,000
0,002
0,004
0,006
0,008
0,010
[η] sp
ez
Elution volume
1,4
1,6
1,8
log
[η] in
tr(fitt
ed)
21 22 23 24 250,000
0,002
0,004
0,006
0,008
0,010
0,012
0,8
1,0
1,2
1,4
1,6
1,8
2,0
log
[η] in
tr(fitt
ed)
20 22 24 26
0,000
0,002
0,004
0,006
0,008
0,3
0,6
0,9
1,2
1,5
1,8
2,1
log
[η] in
tr(fitt
ed)
[η] sp
ez
Elution volume19 20 21 22 23 24 25
0.000
0.002
0.004
0.006
0.008
0.010
0.012
log
[η] in
tr(fitt
ed)
[η] sp
ez
Elution volume
1.0
1.2
1.4
1.6
1.8
21-Arm Poly(NIPAAm) star polymer (Aw 221)
14
5,2 5,3 5,4 5,5 5,6 5,7 5,8 5,9
1,7
1,8
1,9
2,0
2,1
2,2
2,3
2,4Linear Poly(NIPAAm): α = 0.53 7-Arm Poly(NIPAAm) star polymer: α = 0.42 14-Arm Poly(NIPAAm) star polymer: α = 0.27 21-Arm Poly(NIPAAm) star polymer: α = 0.18
log
[η]
log M4,7 4,8 4,9 5,0 5,1 5,2 5,3
1,6
1,7
1,8
1,9 Broad linear Poly(NIPAAm)y = - 1.65638 + 0.68093 x4-Arm Poly(NIPAAm) star polymer(MS 344-4)y = - 0.47662 + 0.42752 xCalculated number of arms f = 3.9
log
[η]
log M
Branching Analysis of Poly(N-isopropylacrylamide) Star Polymers
Sample Average number of arms f α-value PNIPAAm 4-arm star polymer 3.8 0.43 PNIPAAm 7-arm star polymer 6.0 0.42
PNIPAAm 14-arm star polymer 14.5 0.27 PNIPAAm 21-arm star polymer 22.3 0.18
15
Branching Analysis of Poly(N-isopropylacrylamide) Star Polymers
4,8 5,0 5,2 5,4 5,63
6
9
12
15
18
21
24 4-Arm Poly(NIPAAm) star polymer 7-Arm Poly(NIPAAm) star polymer14-Arm Poly(NIPAAm) star polymer21-Arm Poly(NIPAAm) star polymer
f 1
log M
100000 10000000,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5 7-arm star polymer 14-arm star polymer 21-arm star polymer
W (l
og M
)
M / g/mol
number of arms f increases together with molar mass Synthesis mechanism offers no convenient explanation
Molecular weight distributions are monomodal and show no signs of star cross-coupling.
16
Summary - branching analysis could be applied to synthesized star polymers based on poly(sytrene) or poly(N-isopropylacrylamide) - average number of arms is consistent to the functionality of the ATRP initiator - number of arms is not constant over the molecular weight range
Outlook - optimization of the SEC system (especially with respect to the MALLS detector) - analysis of star polymer samples with unknown number of arms
multifunctional initiator
click reaction or core cross-linking
arm-first method (grafting onto)
core-first method (grafting from)
17
• 3- and 8-Arm Poly(styrene) star polymers (PSS)
20 21 22 23 24 25
4,8
5,1
5,4
5,7
6,03-Arm Poly(styrene) star polymer (PSS)
Data of the viscosity dector Data of the multi-angle lightscattering
device
log
M [g
/mol
]
Elution volume [ml]20 21 22 23 24
4,4
4,8
5,2
5,6
6,0
8-Arm Poly(styrene) star polymer (PSS) Data of the viscosity dector Data of the multi-angle lightscattering
device
log
M [g
/mol
]
Elution volume [ml]
• Linear Poly(styrene) (PSS)
18 20 22 24 26 28 304,4
4,8
5,2
5,6
6,0
6,4
6,8 Linear Poly(styrene) (PSS) Data of the viscosity dector Data of the multi-angle lightscattering
device
log
M [g
/mol
]
Elution volume [ml]
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
24 26 28 30
4,0
4,5
5,0
5,5
4-Arm Poly(styrene) star polymer Data of the viscosity dector Data of the multi-angle lightscattering
device
log
M [g
/mol
]
Elution volume [ml]
• 4-Arm Poly(styrene) star polymer (Aw 152)