Biography
 Doctorate in Polymer Chemistry- From University Department of Chemistry, University of Mumbai
1999. Title of the Thesis : Interpenetrating Polymer Network based on renewable resource
polyurethanes-methacrylate
 Post-Doctoral Fellow at Southern Mississippi
Performance Materials, USA
University –School of polymer Science and High
 Presently Working as Head-R & D New technology development-Pidilite Industries Ltd. Since
October 2013.

Professional Experience : 17 +years

Significant exposure in research, management skills, technology, capabilities development and
interpreting research results and technical data.

Proven track record of participating in various research projects with real-time experience in
planning, execution, application of methodologies, documentation and presentation of findings.

Hands-on experience in various chemistries and their application in Areas like Paint, textile, Leather
and wood

Acrylic emulsion synthesis, Oil modification (sulfonation, sulfitation, esterification etc.)

Polyurethane dispersion synthesis and scale up

Silicone and Amino silicone emulsion (softeners for Textile substrate)

Exterior Paints formulation and for Decorative application

Knowledge of Techno commercial aspects of the each.
Company Overview
• Established in 1959, Pidilite Industries has become a
dominant player in consumer and specialty chemicals
• Pidilite is market leader in Construction chemicals, Art and
craft materials
• Some of our biggest brand are
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EFFECT OF DISPERSION PROCESS
AND ANIONIC TO NON-IONIC RATIO ON PROPERTIES OF
WATERBORNE POLYURETHANE DISPERSIONS
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3
CONTENTS
• Process flow for PU dispersion
• Experimental Design
• Critical Phase dispersion Process and impact of anionic: nonionic ratio on phase inversion time
• Effect of ionic content and process variation on:
 Dispersion Properties
•
Particle size and viscosity, Electrolytic stability , shear stability
•
Molecular weight , Drying, Loss and storage modulus
 Polymer Film properties
•
Drying time, Gloss, water, alkali and solvent resistance
•
Hardness , Tensile strength
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Industries Ltd
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Industries
Ltd
Process Flow for PU dispersion
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Schematic representation from -DSM resin Gail Pollano
Experimental Design
Critical
Parameters
PUD by W/O dispersion Process (Water added into the polymer)
EXP 1
EXP 2
EXP 3
EXP 4
EXP 5
EXP 6
Anionic : Non-ionic
EXP 7
EXP 8
Non-ionic:Anioinic
% NCO
5
5
5
5
5
5
5
5
Ratio
1:0
1 : 0.5
1:1
1 : 1.5
1:2
1:0.5
1 : 1.5
1:2
PUD Solids (%)
40
40
40
40
40
40
40
40
Critical
Parameters
PUD by O/W dispersion Process (Pre-polymer added into the water)
EXP 9
EXP 10
EXP 11
EXP 12
EXP 13
EXP 14
Anionic : Non-ionic
EXP 15
EXP 16
Non-ionic:Anioinic
% NCO
5
5
5
5
5
5
5
5
Ratio
1:0
1 : 0.5
1:1
1 : 1.5
1:2
1 : 0.5
1 : 1.5
1:2
PUD Solids (%)
40
40
40
40
40
40
40
40
Terminology in abstract used was
direct process -W/O and Reverse
process O/W
6
Critical Steps-Phase W/O Process
,
•
Phase inversion phenomenon begins when water extends into the hydrophobic areas and their
mobility decreases due to the occurrence of hydrophobic associates in the polymer matrix
•
The polymer -water interfaces then restructure and finally disintegrate into spherical dispersion
particles enclosed by a continuous aqueous phase.
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Ref. Technical seminar, Delhi Feb. 2009
by Dr Dirk Reichel, Evonik
Effect of anionic to non-ionic ratio on
phase inversion time, in W/O Process
Phase W/O time, min
6
5
5
4.5
4.5
4
4
4
4
3.5
3.5
3
3
2
1
0
1:0
1:0.5
1:1
1:1.5
1:2
0.5:1
increasing non-ionic
1:0
1:0.5
1:1
1:1
1.5:1
2:1
increasing anionic
1:1.5
1:2
0.5:1
1:1
1.5:1
2:1
• The Phase inversion phenomenon is observed only in W/O process. In
O/W process this phenomenon was not prominent or not observed.
• Time required to invert the phase (W/O to O/W) decreased with
increasing the non-ionic and increases with increasing anionic
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• With increasing anionic content the particle size decreases and corresponding viscosity
increases.
• At 1:1 concentration of non-ionic and ionic, PUD made with O/W process displayed finer
particle size and lower viscosity
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Effect of Process and Anionic: Non-ionic content
on Shear Stability, @5000RPM/20min
Viscosity @27 °C, CPS spindle 4 RPM 20
7000
6000
5000
4000
3000
2000
1000
0
1:0
1:0.5
1:1
1:1.5
1:2
0.5:1
1:1
1.5:1
2:1
Anionic :nonionic
W/O Initial Visocity, cps
W/O viscosity after shear, cps
O/W Initial Visocity
O/W viscosity after shear, cps
• In both the process composition having higher content of non-ionic shows maximum
viscosity increase, hence least stable.
• Similar phenomenon observed in higher anionic content, however, the extent of
viscosity pickup is low in case of W/O process.
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MOLECULAR WEIGHT AND POLYDISPERSITY
PUD by W/O DISPERSION PROCESS
Anionic:Non-ionic
Ratio
1 : 0 1 : 0.5
1 : 1 1 : 1.5
PUD by O/W DISPERSION PROCESS
Non-ionic:Anionic
1 : 2 1:0.5 1 : 1.5
1:2
Anionic:Non-ionic
1 : 0 1 : 0.5
1 : 1 1 : 1.5
Non-ionic:Anionic
1 : 2 1 : 0.5 1 : 1.5
1:2
Molecular 13912 15291 14514 15105 12600 13500 16268 20028 18230 20736 23163 20993 17799 15435 22630 24989
Weight (Mn)
Molecular 21397 20416 18916 20981 16021 16875 21089 25163 27430 29278 36533 31465 25143 19430 29600 33235
Weight (Mw)
Polydispersity
1.54
1.34
1.30
1.39
1.27
1.25
1.30
1.26
1.50
1.41
1.58
1.50
1.41
1.26
•
No specific trend observed in Mol.Wt. w.r.t. increase in non-ionic
•
There is an increasing trend in Mol. Wt. with increasing the anionic content
•
PUD made with O/W process displayed higher Mol. Wt. and higher polydispersity
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1.31
1.33
Effect of Process and anionic: non-ionic ratio on
Electrolytic stability in 0.2 N HCL
% Coagulum in 0.2 N HCL
70
62.15
59.9
55.85
60
50
48
52
44
42.5
55.85
55.5
42.5
42.2
1:1
0.5:1
49.5
43
40
40
45
34.03
35.1
2:1
1.5:1
29.19
30
20
10
0
1:0
1:0.5
1:1
1:1.5
1:2
Ratio of anionic :non-ionic
W/O
O/W
* Higher the coagulum lesser is the stability
•
In all the cases electrolytic stability (especially in HCL) of the PUD made with O/W process are
•
more stable than W/O process.
As expected the ionic stability increases with increase in non-ionic concentration and decrease
with increasing anionic
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Drying Time, Gloss @60º, Viscoelastic Properties
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Water , alkali and solvent resistance of the polymer film
Spot Test ASTM 1308
Spot test on glass plates with 1 hour recovery: observations based on rating 0=no visible damage, 5=coating completely destroyed
• In both the process the water resistance of the polymer film decreases with
increasing the concentration of anionic and non-ionic.
• The water resistance is highest in absence of non-ionic and lowest at higher
non- ionic content.
• In O/W process after 1:1 ratio decreasing trend was observed in alkali and
water resistance.
• In both the process the solvent resistance improved with increase in non-ionic
content and decreases with increasing an-ionic
• Polymer film of PUD made by O/W process displayed marginally higher
solvent resistance than W/O process
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Pendulum Hardness, Tensile strength and Elongation
• Pendulum hardness of the polymer film decreases with increasing the non –ionic
in both the process . However, the trend is more prominent in O/W process than
W/O.
• The hardness is found to be highest when the anionic concentration became
double. Interestingly, PUD made with W/O process are more harder in all cases
• Irrespective of the process the Tensile and elongation are the highest in absence of nonionic and lowest at 1:1 ratio of non-ionic and anionic.
• In W/O process elongation increases with non-ionic /anionic content
• In W/O process increase in elongation is more prominent with increase in ionic/non ionic content
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SUMMARY
• It was also observed that change in Anionic: Non-ionic ratio of the dispersion has
significant impact on the mechanical properties such as hardness, elongation and
tensile, as well as surface properties like drying time, gloss.
• Solvent , water and alkali resistance are highly dependent on ionic content than
process variation
• In all the compositions the viscoelastic properties such as storage and loss modulus
are independent of the process or Anionic: Non-ionic ratio and showed highly
resilient properties.
• There were no cross over in loss and storage modulus hence no distinct transition
observed. This indicated highly amorphous nature of the polymer
• It is possible to alter the properties and performance of the polyurethane dispersion
using different dispersion process.
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Acknowledgement
The authors are grateful to
Pidilite Industries limited for their support.
Thanks to the Analytical team for valuable inputs, and Yashika for assisting in
experimental work.
08/31/15
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Thanks
For your attention
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References
1. Phase W/O in polyurethane prepolymer-water dispersions, Ph. D. Thesis by
Saw, Lin K, Loughborough University, August 2000
2. Barni, A.; Levi, M. J Appl Polym Sci 2003, 88, 716.
3. M. J. Ferna´ndez-Berridi et al. J. Appl Polym Sci, 2011, 120(4)
4. ASTM D523-89(1999) Standard Test Method for Specular Gloss
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