rajesh phase1 presentation

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

rajesh phase1 presentation

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