Thermo Gravimetric Analysis (TGA) measures the change in mass of a material as the temperature changes. It can be used to determine properties like decomposition temperatures, material composition, and thermal stability. TGA works by continuously measuring the weight of a sample as the temperature increases at a constant rate using a thermo balance. This produces a TGA curve that shows weight changes from reactions like decomposition, oxidation, and dehydration. TGA provides information on degradation rates and temperatures as well as material stability over time and in different environments.

1. Thermo Gravimetric Analysis
(TGA)

2. Definition:
 Thermal Analysis is a branch of materials science by which the physical, chemical ,
and mechanical properties of materials are studied as a function of temperature.
This measurement provides information about physical phenomena, such as phase
transitions, absorption, adsorption and desorption; as well as chemical phenomena
including thermal decomposition, and solid-gas reaction

3. Methods of Thermal Analysis:

4. Thermo Gravimetric Analysis (TGA):
(TGA) Principle:
 Upon heating a certain material, its weight increases or decreases due to certain
reactions like decomposition, oxidation and dehydration.
 It measures the change in mass or weight in function with the temperature or
time with constant heating rate or constant time.
 TGA is based on that the sample is continuously weighted as temperature is
elevated using an instrument called “thermo balance”.
 Data is recorded in the form of curve called “thermo gram”.
 Instruments which can quantify loss of water, loss of solvent, loss of plasticizer are
used and comparing weight loss of material is being followed

5. Types of TGA:
 Dynamic (scanning mode) TGA:
This type of analysis the sample is subjected to conditions of continuous increase in
temperature usually linear with time.
 2) Static (Isothermal ) TGA:
This type of analysis the sample is maintained at a constant temperature for a period
of time during which any change in we

6. TGA Instruments:
Components of thermo balance:
 The balance (electronic micro balance)
 The furnace (heart)
 The programmer (brain)
 The recorder (data collector

8. Factors affecting TGA curve:
Instrumental factors:
 Furnace heating rate
 Furnace atmosphere
Sample characteristics:
 Weight of sample
 Sample particle size

9. TGA Applications:
 Materials characterization through analysis of characteristic decomposition
patterns.
 II. Can be used to evaluate the thermal stability of a material in a desired
temperature range.
 III. Can determine the inorganic or organic content in the sample

10. TGA provides a following useful
information:
 Decomposition temperatures
 Quantitative weight losses
 Compositional analysis
 Long term stabilities
 Flammability properties
 Rates of degradation
 Life time of a product
 Effect of reactive or corrosive atmospheres
 Oxidative stability of material

11. Dynamic Mechanical Analysis:
DMA Principle:
 A sinusoidal strain (oscillating force) is applied to the material at a given frequency,
while the temperature is ramped up or down over a range and deformation is
recorded.
 −50 and 220° C for polymers
 25 and 600° C for glasses and ceramics
 50 and 600° C for metals
 Sinusoidal motion is the repeated motion in which the dynamic clamp repeated the
same movement over and over with maximum and minimum values of forces

12. DMA Instrument:

13. DMA Information:
 Through DMA, some useful properties of materials can be measured, such as the
viscoelasticity, dynamic elastic modulus (E’) and the glass transition temperature
(Tg) in polymers , damping behavior , creep recovery behavior .

15. Glass transition temperature(Tg):
 The temperature at which the maximum in the tan delta peak is observed.
 It defines the point at which the material transitions from an elastic to a rubbery
state