This document discusses different thermal analysis techniques including thermo gravimetric analysis (TGA), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). TGA measures mass changes as a function of temperature. DTA measures the temperature difference between a sample and reference as they are heated. DSC directly measures heat flows into or out of a sample during transitions. The techniques are used to study physical and chemical transitions in materials and have applications in fields like polymers, food, pharmaceuticals, and ceramics for analyzing composition, stability, phase transitions, and melting/boiling points.

1. PRINCIPLE,
INSTRUMENTATION
AND
APPLICATIONS OF
THERMAL ANALYSIS
Group -1
Team members: Rampravesh, Nibedita, Balraj, Periyasamy, Durgakishore, M.S Dhar,
S.Chatterjee , V.G.Prabhu
Seminar by : Vijaykumar S Marakatti
Poornaprajna Institute of Scientific research, Bangalore

2. Outline of talk
 Introduction to Thermal Analysis
 Thermo Gravimetric Analysis -TGA
 Differential Thermal Analysis- DTA
 Differential Scanning Calorimetry -DSC
 Applications

3. Introduction
Change in physical properties of water with increase in temperature

4. Applied thermal analysis techniques
Heat
Change in physical property

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

6. Thermo gravimetric analysis (TGA)
 It is an analysis, the mass of sample is recorded
continuously as its temperature is increased linearly from
ambient to high temperature.
 Mass of material a functions of temperature.
Processes occurring without change in mass (e.g.- Physical
transitions ) cannot be studied by TG.
Reactant(s)  Product(s) + Gas (a mass loss)
Gas + Reactant(s)  Product(s) (a mass gain)

7. Thermal Gravimetric Instrument
Furnace
Balance- hang down here
Auto sampler
Thermocouple
Gas flow
Crucible

8. Best practices for Thermal Analysis
Removal of absorbed water by drying.
 Use purge gas (N2or He) to remove corrosive off-gases
 Use samples with narrow grain size distribution.
 For measurement in vacuum, sample Grain size > 60
mesh
Calibration using the
- Curie Temperature.
-Standard compounds.
 Keep the constant heating rate, same gas atmosphere
and crucible for the analysis.

9. Decomposition of CaCO3 at different
gas atmosphere
Effect of gas atmosphere and crucible on TG
Decomposition of CaCO3 using
different crucible

10. Three factors should be noted when you get a TG curve:
1. General shape.
2. The particular T at which changes in mass occur.
3. The magnitudes of the mass changes.

11. Differential Thermal Analysis(DTA)
 Heat absorbed or emitted by sample is observed
by measuring the temperature difference between
that sample and reference compound as
temperature of both are increased.
ΔT =TS-Tr as function of Temperature.
ΔT ΔH
- Qualitative.
ΔT
Temperature of furnace

12. Differential Thermal Analysis (DTA)
Instrument
Endothermic - heat flows into the sample.
Exothermic - heat flows out of the sample.

13. Interpretation of DTA
ΔH = K * Peak area
K - can be determined by measuring the ΔH and peak area of know metals

14. Limitations of Differential Thermal Analysis
(DTA)
 ΔT determined by DTA is not so accurate (2-3 ̊C).
 Small change in ΔT cannot be determined and
quantified.
 Due to heat variation between sample and reference
makes, it less sensitive.
To improve the above limitations change in the
methodology is required.

15. Differential Scanning Calorimeter(DSC)
Heat flux

16. Power Compensation DSC Cell

17. Applications
Polymer industryFood industry
Pharma industry Research and
development
Ceramic industry
Cosmetic industry

18. V.S.Marakatti et. al .RSC Adv., 2013,3, 10795-10800
Stability of the Materials
Sn(OH)Cl - Catalyst
200 ̊ C- Dehydration
200-400 ̊ C-
Dehydroxylation
400-550 ̊̊C – Formation of
oxide

19. Composition of a Rubber Sample

20. To determine Tg (glass transition temperature)
of Polymers

21. Application in Food Industry
Standard TGA results for Double mint chewing
gum sample
TGA auto stepwise results for Double mint
chewing gum sample
The correct combination of the gum formulation.
Elastomers, glycerin, softening agents, and carbonates, flavoring agents, poly
vinyl acetate

22. Application in determination of phase
transition
113 ̊ C
Rhombohedral to monoclinic
124 ̊C
Melting point
179 ̊C
Liquid phase transistion
446 ̊C
Boiling point
Sulfur element

23. To find the melting and Boiling point of
Materials
Benzoic acid

25. OPEN FOR DISCUSSION
TG ?..
DTA ??
DSC ???ΔH ?
Calibration ?..
DTG
/DTA ???ΔT ?
sample ?
??....