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7/31/2019 Rajesh Phase1 Presentation
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Advisor
Synthesis, Characterization and Ultrasonic
Degradation Of Poly(n-butyl methacrylate-co
-methylacrylate)
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CONTENT
Introduction
Motivation
Method
Results Conclusion
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INTRODUCTION
Polymers are macromolecules build by linking large
number of smaller molecules.
Per capita consumption of polymer in India is 5 kg and
world average is 26 kg.
Most of the polymers are fossil fuel based and their
disposal is a common problem.
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MOTIVATION
Copolymers of n-butyl methacrylate with methyl acrylate
have not been investigated before.
These copolymers may exhibit superior properties than
the homopolymers
Ultrasonic degradation of the homopolymers and
copolymers has been studied in this work.
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METHOD
oExperimental
Monomers
n-Butyl methacrylate Methyl acrylate
oPolymerization
Bulk polymerization at 60oC
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METHOD..
Copolymers of n-butyl methacrylate(BMA) and methyl
acrylate(MA) were formed by bulk polymerization.
Different molar ratio of monomers (BMA:MA)
(40:60, 50:50, 60:40, 75:25) was taken.
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METHOD
oHomo and Copolymers
Poly(n-butyl methacrylate) Poly(methyl acrylate)
Poly(n-butyl methacrylate-co-methyl acrylate)
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SETUPFOR ULTRASONIC DEGRADATION
Water jacket
Ultrasonic horn
Polymer solution
Fig. Experimental setup for ultrasonic degradation
Water in
Water out
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CHARACTERISTICS OF ULTRASONIC DEGRADATION
Mid chain scission due to mechanical stress.
Degradation rate depends on chain length.
No degradation below a limiting molecular weight.
Generally no chemical reaction considered duringdegradation.
Polymer degradation is due to mechanical stress created due
to cavitation.
Kennedy J. E. ,Nature Reviews Cancer5, 321-327 (April 2005)
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GEL PERMEATION CHROMATOGRAPHY
oGPC System
Water 510 HPLC pump
Styragel HR 5E, HR 4, HR 1 size exclusion column
Rheodyne 7725i injector
Water 2410 diffrential refrectrometer
o EluentTetrahydrofuran(THF)
Flow rate: 1ml/min
oCalibration
Narrow molecular weight
polystyrene standard
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THEORETICAL MODEL
Continuous distribution Kinetics was used to determinedegradation rate coefficient.
By ultrasonic degradation polymer breaks frommidpoint.
Population Balance equation for this system will be
( )( ) 2 ( / 2)
k xP x P x
( , )( ) ( , ) 2 ( ') ( ', ) ( ' 2) '
x
p x tk x p x t k x p x t x x dx
t
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Applying moment operation and solving momentequation gives variation in number average molecular
weight with time.
Where,M
no= Initial molecular weight
xl
= limitingmolecular weight
k = Degradation rate constant
0
1 1
ln ln1 1
n ll
n l
M xY kx t
M x
THEORETICAL MODEL
( ) * ( )lk x k x x
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RESULTS
Time evolution profile of Mn
for homo polymers
and copolymers.
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Variation of ln(Y) with sonication time for homo- and copolymers.
RESULTS
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BMA mol % in feed MA mol % in feedRate constant (k)
(mol gm-1min-1)
0 100 2.65
50 50 2.9375 25 3.14
100 0 3.24
Variation in rate constant with the copolymer composition
RESULTS
All experiments were repeated thrice.
Standard deviation of the rate constant was less than 3%
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CONCLUSIONS
In this study, different compositions of poly(n-butylmethacrylate-co-methyl acrylate) were synthesized.
Degradation rate coefficient of these polymers weredetermined from model equation and it follows theorder,
PBMA > PBMAMA-75 > PBMAMA-50 > PMA.
The reason for the above trend has to bedetermined.
Mechanical and thermal properties of thesepolymers have to be determined.
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Thank You
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