This document summarizes a seminar presentation on Thermo Gravimetric Analysis (TGA). TGA is used to determine the changes in mass of a sample as it is heated. It can identify thermal stability, decomposition temperatures, and mass changes associated with desorption, vaporization, or chemical reactions. The presentation outlines the theoretical background, instrumentation, operating principles, data interpretation, and applications of TGA. Examples are given of TGA characterization of polymers like nylon and HDPE to analyze thermal degradation and composition.

1. POST GRADUATE PROGRAM
Fiber Chemistry and Physics
Seminar on:- Thermo Gravimetric analysis (TGA)
Worku Tegegene
First Year MSc. in Textile Chemistry
Submitted to: Assoc. Professor. Adane H.
January,2021
.

2. Outlines
Introduction
Theoretical background
Working Principles
Data Interpretation and Analysis
TGA Characterization
summery
References

3. Introduction
Physical changes :- melting, vaporization,
Heat
Change in property
Chemical changes :- oxidation, decomposition …
Applied thermal
analysis techniques
Thermal Analysis

4. Thermo Gravimetric
Analysis
Mass
Evolved Gas
Analysis
Gas
decompose
Dilatometry volume
Differential Thermal
Analysis
ΔT ΔH
Differential Scanning
Analysis.
Dynamic
Mechanical
Analysis
Physical Properties
Deformation
Laser Flash
Analysis
Thermal
diffusivity

5. TGA
Mass of material as a
functions of temperature.
Reactant(s)  Product(s) + Gas
Gas + Reactant(s)  Product(s)
(a mass loss)
(a mass gain)
Processes occurring without
change in mass cannot be
studied by TG.
Dynamic TGA Static TGA Quasi static TGA

6. Theoretical background
Thermal analysis was first introduced by Le
Chatelier in 1887
The measurement of mass change using
temperature thermogravimetry (TG) was
discovered by Honda, a physicist from Japan.

7. Instrumentation
Restoring Force
Null Detector
weight change

8. Operating Principles
Changes in the mass of a
sample are studied while the
sample is subjected to a
program
Changes in temperature affect the
sample:- desorption, absorption,
sublimation, vaporization, oxidation
It is used in analysis of volatile prod
gaseous products lost,
desorption, absorption,
sublimation, vaporization,
oxidation, reduction and
decomposition ….change
melting, crystallization …no change

9. Data Interpretation and Analysis
Plateau: Thermal stability (AB)
Weight/Mass Loss (BC)
Procedural Decomposition
Temperature (B)
Composition

10. A: No mass change over entire
range of temperature.
B: Desorption/Drying. Mass loss
is
large followed by mass plateau.
C: Single Stage Decomposition
D: Multistage Decomposition
E: Similar to D but either due to
faster heating rates or due to no
intermediaries
F: Atmospheric Reaction, Increase
in mass, reactions like surface
oxidation
G: Similar to Curve F, but product
decomposes at higher
temperatures.

11. no change in weight (AB &CD)
portion BC :- weight change
The weight remains constant
up to a temperature of
473°C, thermally stable
decomposition starts @473°C
The loss in weight continues up to
608°C & ends up @ 608°C
portion CD:-sample remains
constant
Factors affecting the TG curve Instrumental factors :-Furnace heating rate &
Furnace atmosphere
Sample characteristics:- Weight of the sample &Sample particle size

12. Plateau:AB no change in mass
Procedural Decomposition
Temperature:Ti&Tf
Composition:amount/percentage/weig
ht of a compound

13. TGA Characterization for selected polymers
1. nylon 6,6
.
thermal degradation
wight loss for nylon 6,6
under
a
nitrogen
purge

14. . TGA degradation for
two different HDPE
bottles
Weight loss
2. high density polyethylene (HDPE)

15. 3, SAN and butadiene components
compositional analysis of polymeric
blends
significant weight loss
overlapping decomposition
butadiene :-rubbery component

16. Applications of TGA
Thermal Stability:- decomposition mechanism
Material characterization:-
Compositional analysis:- temperature programm
Simulation of industrial processes:-
industrial reactors
Kinetic Studies:- controlling chemistry
Corrosion studies:- studying oxidation

17. summery
TGA analysis is widely used to characterize
and verify materials.
TGA is applicable to most industries.
Environmental, food science, pharmaceutical,
and petrochemical
applications are the mainstay of Thermo
gravimetric Analysis and Evolved Gas Analysis

18. References
Gurdeep R. Chatwal, Sham K. Anand, Himalaya Publishing House, 2002.
Instrumental Methods Of Chemical Analysis: Thermal Methods, pg. 2.701, 5th
Ed.
T. Hatakeyama and F.X. Quinn, Jhon Wiley and Sons Publications, 1999.
Thermal Analysis Fundamentals and Applications to Polymer Science:
Thermogravimetry, pg. 45-71, 2nd Ed.
Coats, A. W.; Redfern, J. P., 1963. "Thermogravimetric Analysis: A Review",
pg. 88: 906–924.
Fleming Polymer Testing And Consultancy, http://www.flemingptc.co.uk/our-
services/dsc-tga/
Sharma B.K. Goel Publishing House “Instrumental Methods of Analysis” pg.
234-237.
Thermal Analysis Dr. S. Anandhan, Asst. Professor, Dept. of Met. And Mat.
Engg., NITK
D. A. Skoog et al., Principles of instrumental analysis, fifth edition, Harcourt
Publishers, 2001.
Analytical Compendium, Chapter 5, Section 2,
http://old.iupac.org/publications/analytical_compendium/Cha05sec2.pdf