quality requirements of the dry-wet spinning process...
TRANSCRIPT
Third End-Year Meeting of STEP-ITN Marie Curie Initial Training Network
Quality requirements of the dry-wet spinning
process –
analysis of raw materials, solutions and fibers
Frank Wendler, Birgit Kosan, Thomas Schulze, Frank Meister
Centre of Excellence for Polysaccharide Research,
Thuringian Institute for Textile and Plastics Research,
Breitscheidstr. 97, D-07407 Rudolstadt, Germany,
Member of the European Polysaccharide Network of
Excellence (EPNOE), www.epnoe.eu
OutlineOutline
•• Shaping of Cellulose Shaping of Cellulose
•• LyocellLyocell processprocess
•• Aims of analyticsAims of analytics
•• Monitoring analyticsMonitoring analytics
•• ThermostabilityThermostability
From Cellulose to shaped bodies
Non-regular cellulose particlese.g. pulp, short fibres
• Cellulose acetate• Cellulose xanthate• Cellulose carbamate
soluble
C
E
L
L
U
L
O
S
E
• Cellulose silyl ether• mixed cellulose ethers
Shaping through regeneration
of dissolved cellulose
Thermoplasticshaping
fusible
DMAc/LiCl
NMMO • H2OBMIMCl
Spinning set-up for manufacturing of
fibreswater
evaporation
Cellulose additives
solvent
spinning dope
nozzle, ∅∅∅∅ ≈≈≈≈ 70 mm filament take-up
spinning pumps
washing
dope storage tank
air gap spinning capillaries
regenerated cellulose filaments
dope preparation
filament
solventrecovery
spinning
Raw materials
Pilotscale plant of Smart Fiber AG, Rudolstadt –Filament after-treatment, drying and winding.
• Process limits : Dope throughput
Take-up velocity
Dope viscosity → Deformation force
Solvent exchange rate
• Process limits : Dope throughput
Take-up velocity
Dope viscosity → Deformation force
Solvent exchange rate
Restricted processing window
Analytical methods
PurityParticle size, pH, surface
Special properties
PolymersSolvent
StabilizersAdditives
Raw materials
Solution stateSpinning behaviour
Thermostability
PulpSuspension
SolutionMelt, Gel
Solutions
PerformanceSpecial features
Fibers, Nano-fibersFilmsBeads
Non-wovens
Shaped bodies
Media
Analytical methods
X-ray (crystallinity)H2O content-CO, -COOH
BioactivityAminespH
...... ...
Adsorption capacityMetalsAmines
Water retention behaviorpHPorosity
White degreeThermostabilityParticle size
Recovery of additiveChromophores (UV/VIS)DP, molar mass
Solvent / metals residuesRheologyH2O content
PorosityDP, molar massα-Cellulose
Surface (Elmi, AFM, ZETA-pot.)MicroscopyMetals
Textil-physical propertiesParticle sizeAsh
FibersSolutionsRaw materials
Raw materials
Solution Fiber
Cellulose – Requirements profile
325 – 395 ml/gViscosity (Cuen)
< 0,5%Ash
> 90%White degree
< 35 µmol/gCO groups
< 25 µmol/gCOOH groups
< 0,5%Soluble content in 20% NMMO
< 100 ppmSum of alkali/earth alkali metals
< 10 ppmSum of heavy metals
(Fe, Cu, Ni, Cr, Mn, Co)
> 90%α-cellulose
480 – 580DP (Cuoxam)
Cellulose –Requirements profile
Not to forget:
Origin – cotton, wood
Processing – sulfite, sulfate
Refining - bleaching
Krässig et al. 2007 Cellulose. In Ullmann`s Encyclopedia of Ind. Chem. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
α-Cellulose content of various paper and dissolving pulp
0
0,05
0,1
0,15
0,2
0,25
0,3
0,0010,010,1110100
Radius [µm]
Cu
mu
lati
ve
in
tru
sio
n [
ml/g
]
Blücher Precolith Ambersorb
Precolith ungem. Kuhera BR255
Hg porosimetry of different charcoals
Extraordinary effect on adsorption capacity
but enhanced thermal
degradation !
Wendler F., Kolbe A., Meister F., Heinze T. 2005. Macromol. Mat. Eng. 290: 826-832.
200 nm
MicroSilver BG™- porös, 80 – 140 nm
NanoSilver BG™- kolloidal, 5 – 20 nm
Wendler F., Meister F., Montigny R., Wagener M. 2007. FIBRES & TEXTILES in Eastern Europe 15, No. 5-6 (64 - 65): 41-45.
Extraordinary effect on fiber bioactivity
but enhanced thermal
degradation !
Raw materials
Solution Fiber
Surface topography on 1 x 1 µm sample size for a cellulose/xanthan fiber from EMIMac (Ra = roughness)
NMMORa 4.8 nm
NaOHRa 20.6 nm
EMIMacRa 0.93 nm
Prof. Dr. Stana-Kleinschek, University of Maribor
Atomic force measurement (AFM)
0
50
100
150
200
250
300
350
400
0 10 20 30 40 50 60 70 80 90
CHI [°]
Inte
nsität
[cps
]
Total scan with χχχχ sectionsthrough the reflexes at 2θθθθ
0
50
100
150
200
250
300
350
400
30 50 70 90 110 130
Chi [°]
Inte
nsität
[cps]
0
200
400
600
800
1000
1200
1400
1600
1800
0 10 20 30 40 50 60 70 80 90
CHI [°]
Inte
nsität
[cps]
Dr. Thomas Schulze, TITK
Raw materials
Solution Fiber
cell. xanthate/NaOH cellulose acetate/ cellulose/Cuoxam cellulose/ cellulose/
acetone NMMO/H2O BMIMCl
aqueous acids solvent evaporation aqueous acids water water(water)
irregular irregular/fibrous fibrous fibrous fibrous
Target: Dissolution of cellulose
→ Interaction of polymer and solvent is of fundamental importance for
understanding and perception of proceeding processes in polymer dissolution
→ structure of regenerates, structural changes of polymer and solvent, dope
properties and shaping behaviour should be discussed
→ different fibrous structures of regenerated films regarding to precipitating
structures
Michels, C., Kosan, B. 2005. Lenzinger Berichte 84, 62
Herlinger, H., Grynaeus P., Hirt P. et al. 1990. Lenz. Ber. 69, 65.Cibik T. 2003. Investigation of the system NMMO/H2O/Cellulose. Thesis, TU Berlin. Michels C., Kosan B. 2005. Lenz. Ber. 84, 62.
→ high ordered dissolved state is detectable in viscous NMMO melts containing different amounts of water
→ connected to the distinctive H-bond system existing in solid state
→ at about 62 % NMMO a stable 2,5 hydrate is formed
→ NMMO forms a second stable hydrate, NMMO monohydrate
→ high ordered state won’t be significant changed by the addition of polymers like cellulose but slightly disturbed
→ NMMO monohydrate dissolves cellulose fast macroscopic
- 1,5 n H2O
t = 0 minFibers dispersed in 60 % NMMO
t = 60 minAfter adjustment 80 % NMMO
t = 90 minAfter adjustment 80 % NMMO
t = 120 minAfter adjustment 80 % NMMO
0
20
40
60
80
100
0,1 1 10 100
Particle diameter [µm]
Su
m d
istr
ibu
tio
n [
%]
0
80
160
240
320
400
Den
sit
y d
istr
ibu
tio
n
Cellulose concentration 12,3 %Eucalyptus, DP 563 Zero shear viscosity 9910 PasParticle volume 1,3 µl/l solution Max. Particle diameter 18 µmColour number 12Filter amount 31
Particle analysis: Sum and density distribution of a cellulose/NMMO solution
5
10
15
20
25
0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9 2,1 2,3 2,5
Fineness [dtex]
Ma
x. p
art
icle
siz
e [
µm
]
Particle size criterion:
< 40 µm fiber< 20 µm filament
25
1. Determination of the zero shear viscosity
rotation mode with controlled shear stress (90 Pa)
2. Characterisation of the flow behaviour
oscillation mode (frequency sweeps between 0.046 and 14.7 Hz) at different temperatures for the calculation of master curves (storage and loss moduli as well as the complex viscosity depending on frequency respectively angular rate, referring to a reference temperature, i.e. 85°C)
determination of the cross over between storage and loss modulus and the plateau moduli (plateau value of the storage modulus)
calculation of the weighted relaxation spectra (relaxation
time λm, information on the molecular mass distribution of the polymers which are involved in the solution stateby rheological methods)
Rheometry of cellulose dopes is targeted to …
© maaja Design
© maaja Design
© maaja Design
Microscopic images by polarisation light of cellulose solutions in NMMO (16,5%) and EMIMAc (24,9%)
Kosan B., Schwikal K., Meister F. 2010. Cellulose 17: 495–506
2,5
2,7
2,9
3,1
3,3
3,5
3,7
3,9
4,1
4,3
4,5
0,0025 0,0026 0,0027 0,0028 0,0029 0,003
1/T [1/K]
lg n
[P
a s
]81°C
76°C
Viscosity measurement of cellulose/EMIMAc solutions at differenttemperatures at a shearing rate of 0.5 s-1 (Arrhenius plot)
28,0%
24,9%
19,2%
Main actions and degradation reactions in the system cellulose/NMMO
NMMOlabilityoxident
Celluloseendgroupssugar acidsradicals
Hydrogen bond systembetween cellulose and NMMO
Conta-
minationsIronCopper O
OH
OH
HOCell-O
O-Cell
ON
O
O
OH
OH
HOCell-O
O-Cell
Properties of additives
pH value -COOH, -NH2
structurepore sizeparticle size porosity
Temperature+
Pressure
O
OH
OH
HO
OH
O
OH NO
O
Cell-O
+
NO
OHOCell-
HO
OH
OH
Thermal degradation
Oxidation of cellulose, deoxygenation of NMMO
Radical reaction
Polonovski type reaction
NO
OAA
NO
O-Acyl
NOB
CH2 + O-Acyl H-B+
OH-
NO CH2OH
NO H
+ HCHO
AA = acylating agent
B = Base
NO
O
Fe(II)+ +.
Fe(III)NO2 H+
- H2O
O
NO HNO H2O+
_
+NO 1/3 1/3 1/32/3 + + CO2
Lukanoff, B., Philip, B., Schleicher, H. 1984. Acta Polymerica 35, 339-343.
Taeger, E., Franz, H., Mertel, H. 1985. Formeln, Fasern, Fertigware 4, 14-22.
Buijtenhuijs, F.A., Abbas, M., Witteveen, A.J. 1986. Papier 12, 615-619.
Rosenau, T., Potthast, A., Sixta, H., Kosma, P. 2001. Prog. Polym. Sci. 26, 1763-1837.
Wendler F., Graneß G., Heinze T. 2005. Cellulose 12/4: 411-422.
40 °C, 1min
0,8×2,0 magnification with microskope SMC 4, Fa. Ascania, heating table Linkam.
104°C, 5 min
112°C, 15 min
116 °C, 20 min
119 °C, 22 min
123 °C, 26 min
126 °C, 28 min
129 °C, 31 min
131 °C, 34 min
138 °C, 41 min
141 °C, 44 min
145 °C, 48 min
147 °C, 50 min
149 °C, 52 min
149 °C, 53 min
150 °C, 54 min
150 °C, 54 min
150 °C, 54 min
150 °C, 55 min
150 °C, 60 min
150 °C, 70 min
150 °C, 75 min
150 °C, 75 min
150 °C, 80 min
150 °C, 90 min
Accidere ex una scintilla incendia passimTitus Lucretius Carus (96 – 55 v. Chr.)
'Big fires often arise from a little spark'
Problem of industrial reactors:
Heat development ~ Volume ~ r3Vessel
Heat release ~ Area ~ r2Vessel
Vessel volume Cooling time for 1 K
Cooling speed K/min
10 ml 11 s 5,5
100 ml 20 s 3
1000 ml 2 min 0,5
2,5 m3 21 min 0,047
25 m3 233 min 0,0043
Phi = (ms * cs + mg * cg) / (ms * cs),
-50
-40
-30
-20
-10
0
10
20
25 45 65 85 105 125 145 165 185 205 225 245
Temperature [°C]
En
thal
py
[mW
]
5%Cell., BMIMCl
5%Cell., NMMO
NMMO
DSC measurements of NMMO and cellulose solutions in NMMO and BMIMCl
Fast screening method, 5 - 20 mg sample massOnset-Temperature, reaction enthalpy
0
50
100
150
200
250
300
0 50 100 150 200 250 300 350 400
Time [min]
Te
mp
era
ture
[°C
]
0
5
10
15
20
25
30
35
40
45
Pre
ss
ure
[b
ar]
p
-0,5
0
0,5
1
1,5
2
2,5
30 60 90 120 150 180 210 240
Temperatur [°C]
dp
/dt
[ba
r/m
in]
-0,5
0
0,5
1
1,5
2
2,5
dT
/dt
[K/m
in]
dp/dt
dT/dt
-0,05
0
0,05
0,1
0,15
0,2
100 120 140 160 180 200
Temperatur [°C]
dp
/dt
[bar/
min
]
-0,05
0
0,05
0,1
0,15
0,2
dT
/dt
[K/m
in]
Ton = 160°C
Dynamic measurements by means of the mini-autoclave:Sample mass 2 g, 0,75 K/min, 30 – 300°CTemperature and pressure !
Onset temperature (Ton): First thermal activity
Mini - autoclaveRADEX - Reaction calorimeterRapid Detector for Exothermic ProcessesFa. Systag/CH
Calorimetric measurements
131
142
146
151
160
145
163
120 130 140 150 160 170
9% Cellulose/NMMO modified w ith reactive activated
charcoal
11% Cellulose/NMMO + 50 ppm Fe(II)
11% Cellulose/NMMO + 50 ppm Fe(III)
9% Cellulose/NMMO modified w ith acidic ion exchange
resin
11% Cellulose/NMMO + NaOH, propyl gallate
11% Cellulose/NMMO
NMMO monohydrate
Onset - Temperature [°C]
Calorimetric measurements - mini-autoclave
Comparison of onset - temperatures
-0,2
-0,1
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0 10 20 30 40 50 60 70 80 90
Time [h]
Pre
ssu
re [
bar]
10% cellulose + 5% charcoal in NMMO
10% cellulose + 2% ZnO in NMMO
11% Cellulose in NMMO
10% cellulose + 5% charcoal in BMIMCl
Calorimetric measurements: SEDEX oven, Fa. Systag/CH
Adiabatic calorimetry: Changes in isoperibolic pressure of cellulosesolutions at 110°C over 96 h.DEWAR vessel with 300 g sample mass
-100
0
100
200
300
400
500
600
0 5 10 15 20 25 30
Time [min]
Ab
so
rpti
on
[m
AU
]
Distillate of cellulose/NMMO solution
High Performance Liquid Chromatography (HPLC)
N
O
H
N
O
OH
N
OH
NN
OH
CHO
N
O
Wendler F., Kolbe A., Meister F., Heinze T. 2005. Macromol. Mat. Eng. 290: 826-832.
High Performance Liquid Chromatography (HPLC)
Comparison of onset temperature (Ton) and concentration of N-methylmorpholine
(NMM) in destillates of Lyocell solutions modified with activated charcoal.
0
2000
4000
6000
8000
10000
12000
0,9 1,8 2,7 3,6 4,5 6,8 8,6
Concentration [%]
NM
M [
mg
/l]
120
125
130
135
140
145
150
T o
n [
°C]O
N
CH3
Ton
Todi L.-N., Wendler F., Meister F., Heinze T. 2011. Analytical investigation of various cellulose-ionic liquid systems. 2nd
EPNOE Conference – Polysaccharides as source of advanced and sustainable products, Wageningen, NL
Qualitative determination of the volatile compounds in the Cellulose/EMIMAc system (Head-space-GC/MS)
Electron Spin Resonance Spectroscopy
H50 G
R2
*CH
3
R3 H
*CO
R2
R2
R2R
2R3
R3
Experimental ESR spectra of NMMO/cellulose solution recorded after 16 min excimer laser (� = 248 nm) photolysis at 77 K.
Konkin A., Wendler F., Roth H.-K., Schrödner M., Meister F., Heinze T., Aganov A., Garipov R. 2006. Magn. Reson. Chem. 44/6: 594-605.
mN
I= 0
mN
I= - 1
- NO*
-
ACH2 A
CH3
H 50 G
2A2
(N)
experiment
simulation
- CH2- NO
*- CH
3
mN
I =1
2AN
1
105 K
Experimental ESR spectra recorded after 16 min irradiation at 105 K and their simulations Constructed spectra of pure -NO٠ radical and R_NO٠-R'
.CH2 CH2 N CH3CH2OCH2
.O
CH3
O.
CH2 CH3N+
CHOCH3.
CH2 CH OH
CCH3
O
H
.
H+
O
NO
Suggested pathway
Electron Spin Resonance Spectroscopy
Changes in UV/VIS spectrum of cellulose/NMMO solutions heated at 120°C
After 400 min
Immediately after preparation
∆ E
Observation wave length
UV/VIS spectrometry
Heating coil
Sample
Copper block
Aperture slitQuarz window
Varistors
34,0
24,5
18,5 I0
Distance ring: 0,35 mm
Wendler F., Graneß G., Heinze T. 2005. Cellulose 12, 411-422
Design of the cuvette for heating
of cellulose
solutions
140°C
130°C120°C
110°C
100°C
Extinction-time curves of a cellulose/NMMO solution at different
temperatures. Determined at λλλλ 400 nm.
Extinction
Time [min]
UV/VIS spectrometry
90°C
100°C
110°C
120°C
130°C
140°C
Extinction-time curves of a cellulose/NMMO solution modified with an acidic ion
exchange resin at different temperatures. Determined at λλλλ 400 nm.
Extinction
Time [min]
UV/VIS spectrometry
Exothermicity: temperature development exclusively caused by the exothermic reaction accompanied by pressure rise.⇒ sporadically, uncontrollablly, autocatalytically running reactions
Determination by calorimetric and spectroscopic methods:Pressure and temperature rise are overlayed by the pyrolyse
Three steps:segregation oscillation degradation
Low thermal conductivity Compensation by convection
0
0,5
1
1,5
2
2,5
3
3,5
0 50 100 150 200 250 300 350 400
Time [min]
Ab
so
rba
nc
e
12% cellulose in EMIMac, recycled
12% cellulose in EMIMac, new
UV/VIS spectrometry
Extinction-time curves of a cellulose/EMIMAc solution at 120°C, λλλλ 400 nm.
T [
°C]
0
20
40
60
80
100
120
140
0 100 200 300 400t [min]
p [
mb
ar]
0
20
40
60
80
100
120
140
p T
Wendler F., Graneß G., Project reports 2008/2010Wendler F., Graneß G., Büttner R. 2005. DE 102005 010560 B4, 04.03.2005.
Special designed calorimetric cell.
Changes in isoperibolic pressure of 11% cellulose solution in NMMO at 130°C over 400 min, 3 - 4 g sample mass
Adiabatic calorimetry: Changes in isoperibolic pressure of 11% cellulosesolution in NMMO at 110°C over 96 h.DEWAR vessel with 300 g sample mass
0
20
40
60
80
100
120
0 25 50 75
Time [h]
Te
mp
era
ture
[°C
]
0
0,05
0,1
0,15
Pre
ss
ure
[b
ar]
0
50
100
150
200
250
300
350
400
0 2 4 6 8 10 12 14 16
Time [h]
Te
mp
era
ture
[°C
]
0
0,5
1
1,5
2
2,5
Pre
ss
ure
[b
ar]
Sample temperature
Oven temperature
Pressure
Adiabatic calorimetry: Changes in isoperibolic pressure of 11% cellulosesolution in NMMO at 130°C over 96 h.DEWAR vessel with 300 g sample mass
0
0,2
0,4
0,6
0,8
1
1,2
1,4
0 2 4 6 8 10 12 14
Time [h]
dT
/dt
[K/m
in]
0
0,01
0,02
0,03
0,04
0,05
dp
/dt
[bar/
min
]
dT/dt
dp/dt
Adiabatic calorimetry: Changes in isoperibolic pressure of 11% cellulosesolution in NMMO at 130°C over 96 h.DEWAR vessel with 300 g sample mass
Target:
Dissolution of cellulose
and
to keep the cellulose in solution
under practical conditions:
Time
Temperature
1 mm 1 2 3 4
Reasons for dissolution / segregations:
• Solution stateNetworks, gelic behaviorSchurz J. 1979. Papier 12: 558-561
• MorphologyCrystalline/amorphous regions, surface properties, porosityKlemm D., Philipp B., Heinze T., Heinze U., Wagenknecht W. 1998. Comprehensive Cellulose
Chemistry. Wiley, Weinheim.
• Ionic interactionsHydogen-bond network (NMMO), complexations(LiCl/DMAc, Cuoxam, Cuen, FeTNa)Bechtold T., Manian A.P., Oeztürk H.B. et al. 2011. 2nd EPNOE conference, Wageningen, NL
• Amphiphilic character of celluloseLindman B., Karlström G., Stigsson L. 2010. J. Mol. Liquids 156: 76-81.
Bergenstråhle M., Brady J. W. et al. 2010. Carbohydr. Res. 345: 2060-2066.
... more practical reasons:
• Time
Dwell time in reactor, tubes
• Temperature
• Water content
• Cellulose concentration
• Type of cellulose
DP, MWD
• Solvent
Co-solvent, purity
• Stabilizers
• Functional additives
SAP, char coal, carbon black, ceramics, Ag NPWendler F., Graneß G., Büttner R., Meister F., Heinze T. 2006. J. Polym. Sci. Part B: Polymer Physics,44/12: 1702-1713.
Spinning stabilitySpinning stability
Conclusions
Monitoring of Lyocell solutions ensures
Conclusions
Monitoring of Lyocell solutions ensures
Requested fiber performanceRequested fiber performance
RecyclabilityRecyclability
Thermal stabilityThermal stability
Choice of appropriate raw materialsChoice of appropriate raw materials
Process efficiencyProcess efficiency
Acknowledgements: Financial support was granted by the EC 6th framework program, contract number NMP3-CT-2005-500375 (project acronym: Polysaccharides), the EC 7th framework program, Marie Curie Initial Training Networks (ITN), call: FP7-PEOPLE-2007-1-1ITN, contract number 214015 (project acronym: STEP) and the German Ministry of Economics and Technology (INNO-WATT IW091005). Furthermore the authors thank all who were involved in the works and have contributed to the realization of the results.
Thank you very much for your attention!
Special thanks to:
Birgit Kosan
Marcus Krieg
Michael Mooz
Thomas Schulze
Frank Meister