2. Page 2
CANNON Instrument Company
Main Points
• Measurements of polymer solution viscosity is a
fundamental tool for polymer characterization.
• There is a strong correlation between polymer
solution viscosity and polymer molecular size/weight.
• The measured intrinsic viscosity, 𝜂𝜂 , is used
effectively to make comparisons among recycled and
sustainable plastics.
𝜂𝜂 = 𝐾𝐾 � 𝑀𝑀𝑎𝑎
✯ properties improve at higher MWs
✯ processing is impacted by MW
3. Page 3
CANNON Instrument Company
Dilute Solution Viscosity (DSV)
The Concentration Continuum
zero
polymer
zero
solvent
straight
solvent
polymer
melt
𝐶𝐶∗
no chain
interactions
increasing contact
between chains
increasing extend of
chain entanglements
𝐶𝐶‡
DILUTE SEMI-DILUTE CONCENTRATED
4. Page 4
CANNON Instrument Company
The Utility of Intrinsic Viscosity, [η]
𝜂𝜂 = 𝐾𝐾 � 𝑀𝑀𝑎𝑎
Mark-Houwink-Sakurada-Kuhn
𝑀𝑀 =
𝜂𝜂
𝐾𝐾
�
1
𝑎𝑎
solving for molecular weight, M
𝜂𝜂 depends on relative viscosity, 𝜂𝜂𝑟𝑟
𝜂𝜂𝑟𝑟 =
𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣
𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣
=
𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡
𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡
=
𝑡𝑡
𝑡𝑡𝑜𝑜
5. Page 5
CANNON Instrument Company
miniPV®—fully automated viscometer
great precision
• stable
• simple
time consuming
• rinsing/drying
• observing
manual viscometer automated viscometer
• speed
• safety
• range
‘+’
auto
sampler
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CANNON Instrument Company
IV is a Surrogate for MW
𝜂𝜂 = 𝐾𝐾 � 𝑀𝑀𝑎𝑎 𝑀𝑀 =
𝜂𝜂
𝐾𝐾
�
1
𝑎𝑎
K, a
Correlate processing and properties
directly with Intrinsic Viscosity.
required
to get MW
directly
measured
Target applications based on the
measured Intrinsic Viscosity.
adds a level of uncertainty
7. Page 7
CANNON Instrument Company
IV Ranges of PET Grades
PET grade Intrinsic Viscosity [dL/g]①
Fiber grade 0.40 – 0.70
Film grade 0.70 – 1.00
Bottle grade 0.70 – 0.78
Water and soft drink bottle grade 0.78 – 0.85
Carbonated drink bottles 0.73 – 0.80
②
①https://blog.icpg.co/the-importance-of-controlling-intrinsic-viscosity-in-extruded-pet
②Awaja F, Pavel D. Recycling of PET. Eur Polym J. 2005;41(7):1453‐1477 “However, in the last years, requirements have shifted
towards higher values.”
NOTE: In Europe and tropical areas, required IV > 0.80 dL/g.
INTRINSIC VISCOSITY is the basis for ranking PET
for processing performance and physical properties.
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CANNON Instrument Company
Study of rPET content in Bottles
Alvarado Chacon F, Brouwer MT, Thoden van Velzen EU. Effect of recycled content and rPET quality on the properties of PET bottles,
part II: Optical and mechanical properties. Packag Technol Sci. 2020;1–11
Method: ASTM D4603 | IV of PET by Glass Capillary Viscometer
9%
10%
14%
14%
NA
9%
14%
2%
IV scrutinizes blending with rPET
before
processing
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CANNON Instrument Company
Chain Extenders
Case Study | HiTerra rPET Revive
Yellow Index
Intrinsic Viscosity for
duplicate measurements
Sample - polyethylene terephthalate avg. IV std. dev. % change YI Notes
PET - Virgin 0.68 0.007 -6.96
PET - single pass 0.55 0.006 -19.1 % 0.39
PET - double pass 0.51 0.006 -25.0 % 3.2
PET - single pass + 0.5% HiTerra rPET Revive 0.63 0.002 -7.4 % 0.08
PET - double pass + 0.5% HiTerra rPET Revive 0.58 0.003 -14.7 % 2.26 No additional additive
added for this pass
Sample - polybutylene terephthalate avg. IV std. dev. YI Notes
PBT - Virgin 0.74 0.002 -0.97
PBT - single pass 0.73 0.007 -1.4 % 3.6
PBT - double pass 0.75 0.026 1.4 % 5
PBT - single pass + 0.5% HiTerra rPBT Revive 0.79 0.010
6.8 %
0.07
PBT - double pass + 0.5% HiTerra rPBT Revive 0.78 0.006
5.4 %
2.65 No additional additive
added for this pass
“Revive”
improves
IV stability
“Revive”
increases
IV
by Techmer PM
10. Page 10
CANNON Instrument Company
Chain Extenders
Case Study | HiTerra rPET Revive
Sample - recycled polyethylene terephthalate IV % change YI Notes
rPET 0.57 9.88
rPET - single pass + 0.5% HiTerra rPET Revive 0.61 7.0 % 9.37
Sample - polyethylene terephthalate (higher IV) IV % change YI Notes
PET - Virigin 0.84 5.35
PET - single pass 0.78 -7.1 % 14.81
PET - single pass + 2.5% HiTerra rPET Revive 0.94 11.9 % -4.16
2.5% is a higher LDR than
normally recommended,
but has dramatic
yellowness improvement
IV increases
for rPET
YI: 14.81-4.16
virgin w/Revive
at 2.5%
Significant IV increase at higher
Revive loading (let down ratio).
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CANNON Instrument Company
IV in Novel & Innovative Applications
• PVB – repurpose of laminated glass
– adhesive, paint additive, solar panel coating
• PET – Fabric Recovery
• Polymerization from Biomass
– Uses microorganisms found in the ocean to convert air and greenhouse
gas into a natural biomaterial
consolidation regeneration reintegration
end-of -life in-use product
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CANNON Instrument Company
Takeaways
direct measurement of IV
unattended & safe operation
The Fully Automated Viscometer provides:
high quality data with exceptional precision
stable design & fast results
“Owing to the superb precision of viscosity measurements, the
intrinsic viscosity can easily be measured to three significant
figures, which makes it by far the most precise polymer
characterization method.” Polymer Physics, page 35
13.
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CANNON Instrument Company
Background
Hermann Staudinger (1930’s) performed dilute solution
viscosity (DSV) measurements to support his idea that polymers
were long sequences of covalent bonds rather than aggregates
of small molecules that formed a colloidal system.
Others have built on his ideas until we now
have an established relationship between
intrinsic viscosity and molecular weight.
𝜂𝜂 = 𝐾𝐾 � 𝑀𝑀
Staudinger index:
𝜂𝜂 = 𝐾𝐾 � 𝑀𝑀𝑎𝑎
intrinsic viscosity:
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CANNON Instrument Company
Solution Preparation System (SPS)
Solvent Dispenser
Analytical Balance
Software for controlling
devices and calculating
concentration
Automation for Accurate Concentrations
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CANNON Instrument Company
The Solvent Motion –
Laminar Flow
stationary plate
pumping force
pulling force
Laminar flow of liquid between parallel plates:
Laminar flow of liquid pumped through tube:
y
x
x
y
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CANNON Instrument Company
The Solvent Motion –
Laminar Flow
force of gravity
Laminar flow of liquid in a vertical tube:
x
y
“particle” is
experiencing a
velocity gradient.
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CANNON Instrument Company
The Particle Motion - Rotation
Coordinate system positioned at the “particle” center.
y
x
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CANNON Instrument Company
The Macromolecular Motion
Herbert Morawetz, Macromolecules in Solution, page 291
The theories for
DSV require that
these motions
and deformations
must not be
influenced by
neighboring
polymer chains.
y
x
20. Page 20
CANNON Instrument Company
Molecular
Weight
Mc
c*
dilute
solution
semi-dilute & concentrated
solutions
development of
chain entanglements
Interaction Between Polymer
Chains – the Situation in Solutions
Concentration
21. Page 21
CANNON Instrument Company
The Meaning of Intrinsic Viscosity
The intrinsic viscosity of a polymer solution acts as a
measure of the additional energy loss due to rotation
of the macromolecule in the flowing liquid.
from Structure of Macromolecules in Solution
The macromolecule must be free to rotate:
→ cannot be encumbered by entanglements
→ only interaction is with solvent (small) molecules
“… the only way of separating them sufficiently is by
dissolution in a liquid of low molecular weight.”
22. Page 22
CANNON Instrument Company
Measurement of Intrinsic Viscosity
Polyphthalamide
in phenol/TCE
at 30 °C
0.72
0.77
0.82
0.87
0.92
0.97
1.02
0.00 0.50
(η
r
-
1)/c
&
ln(η
r
)/c
(dL/g)
concentration (g/dL)
H - 0.2 g/dL
K - 0.2 g/dL
H - 0.2 g/dL (dup)
K - 0.2 g/dL (dup)
H - 0.4 g/dL
K - 0.4 g/dL
H - 0.4 g/dL (dup)
K - 0.4 g/dL (dup)
H - 0.6 g/dL
K - 0.6 g/dL
H - 0.6 g/dL (dup)
K - 0.6 g/dL (dup)
H - 0.8 g/dL
K - 0.8 g/dL
H - 0.8 g/dL (dup)
K - 0.8 g/dL (dup)
Huggins
Kraemer
Mv = 20,400 Daltons
IV = 0.797 dL/gm
𝑀𝑀 =
𝜂𝜂
𝐾𝐾
�
1
𝑎𝑎
K = 0.000364
a = 0.75
Polymer Handbook,
page VII/37
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CANNON Instrument Company
Averages of the MWD
Frank McGrew, Journal of Chemical Education, vol 35, issue 4