Include introduction classification and characterization of polymer for PG students

1. Characterization of Polymer
By
Dr. Harshali G. Wankhade
Assistant Professor
Department of Chemistry
Shri Shivaji Science College Amravati

2. GraftCopolymer
It is macromolecules of two or more different chemical chain in which a chain
(backbone) has multiple branches formed form macromolecular chains with
a chemical composition different from that of the backbone.
Grafted chain may be homopolymer or copolymer.
Example – High impact polysterene ( where polysterene backbone grafted
with polybutadiene chain.)

3. BlockCopolymer
A block copolymer is a copolymer formed when the two monomers cluster together
and form blocks of repeatating unit.
~A-A-A-A-A-A-A-B-B-B-B-B-B-B-A-A-A-A-A~
The intermediate unit at which the two homopolymer chains are linked is called a
junction block.
A diblock copolymer contains two homopolymer blocks whereas a triblock
copolymer contains three distinct blocks of homopolymers.
An example of such a polymer is acrylonitrile butadiene styrene, commonly
referred to as SBS rubber.

4. RandomCopolymer/ Statistical Copolymer
A random copolymer is one in which the monomer residues are located randomly in
the polymer molecule.
-A-B-B-B-A-A-B-A-B-A-A-A-B-A-B-B
It follows the statistical rule. If the probability of finding a given type of monomer
redidue at particular point in the chain is equal to the mole fraction of that
monomer residue in the chain, then the polymer may be referred to as truly
random copolymer.

5. Synthesisof graft copolymer
Graft copolymers can be obtained by three different methods: in-
1. chain metalation of a polymer backbone and subsequent addition of the graft-
forming monomer (“grafting from”),
2. linking of living anionic polymers with in-chain functional groups on a polymer
backbone, (“grafting onto”),
3. Copolymerization of a macromonomer with the backbone-forming monomer,
(“grafting through”).

6. Grafting from

7. Grafting onto
Grafting through

8. Synthesisof Blockcopolymer
A. General Synthesis Strategies-
Two methods have been developed for the synthesis of AB diblock copolymers:
1. sequential addition of monomers
2. coupling of two appropriately end-functionalized chains.
Sequential addition of monomers
The living chain from the polymerization of the first monomer must be able to
efficiently initiate the polymerization of the second monomer. Another important
requirement is that the conversion of the first monomer must be quantitative in
order to achieve control over the molecular weights as well as chemical and
structural homogeneity.
B. Anionic polymerization-

9. Synthesisof Randomcopolymer
Random copolymer is synthesized by free radical Mechanism.

10. Characterization of polymer
Nuclear magnetic
resonance (NMR)
NMR identifies the nature of the group and the site where the graft
is attached to the polymer backbone. 1H NMR and 13C NMR are
utilized depending on the chemical nature of the material
Infrared
spectroscopy (IR)
Identification of specific functional groups grafted to backbone. It
can also be used to quantify grafting functionalities in modified
polyolefins by determining the intensity of the characteristic
reference bands in the sample, and compare them to a calibration
curve of known concentrations of the same functional group
X-ray diffraction
(XRD)
XRD is useful for the study of crystallinity of chemical substances.
Polymer grafting is associated with changes in XRD patterns
Differential
scanning
calorimetry (DSC)
This is utilized to evaluate changes in crystallinity through the
thermal behavior between backbones and grafted materials.
Thermogravimetric
analysis (TGA)
This is used to study changes in thermal decomposition profiles
between backbones and grafted materials.

11. Thermogravimetric Analysis(TGA)

12. TGA measurements provide valuable information that can be used to select materials
for certain end-use applications, predict product performance and improve product
quality. The technique is particularly useful for the following types of measurements:
Compositional analysis of multi-component materials or blends
Thermal stabilities
Oxidative stabilities
Estimation of product lifetimes
Decomposition kinetics
Effects of reactive atmospheres on materials
Filler content of materials
Moisture and volatiles content

14. Differential ScanningColorimetry

18. Differential Thermal Analysis(DTA)
Involves the technique of recording the difference in temperature between
the test and reference material time being constant for both.
Hence the difference thermogram consists record of difference in
temperature.

25. ThermomechanicalAnalysis(TMA)
This technique used to measure dimensional changes of solid or liquid
materials as a function of temperature, time and applied force is the
thermomechanical analysis (TMA).
This method is often used to measure a material's
I. Coefficient of thermal expansion (CTE)
II. Glass transition temperature (Tg)
III. (compression) modulus.

26. Nuclear Magnetic Resonance Spectroscopy (NMR)

27. Polymer Composition Analysis

31. Infra-redSpectroscopy(IR)
Material Properties of Polymer
Chemical Structure
Configuration
Conformation
Physical Structure
Dynamics

36. The UV visible absorption and emission spectra and excited state lifetimes
of polymers are sensitive to chemical structure, polymer conformation and
molecular environment and thus information concerning these properties
is accessible by electronic spectroscopy.
UV/Vis spectroscopy is routinely used in analytical chemistry for
the quantitative determination of different analytes, such as transition
metal ions, highly conjugated organic compounds, and biological
macromolecules. Spectroscopic analysis is commonly carried out in
solutions but solids and gases may also be studied.
Ultra-violetVisible Spectroscopy(UV-Visible)