Thermogravimetric analysis:

Interpretation of TGA Curves:

TGA curves are typically classified into seven types according to their shapes. Figure 23.03 shows schematic of various types of TGA curves.

Figure 23.03: Schematic of various types of TGA curves.

• Curve 1: No change: This curve depicts no mass change over the entire range of temperature, indicating that the decomposition temperature is greater than the temperature range of the instrument.

• Curve 2: Desorption / drying: This curve shows that the mass loss is large followed by mass plateau. This is formed when evaporation of volatile product(s) during desorption, drying or polymerization takes place. If a non-interacting atmosphere is present in the chamber, then curve 2 becomes curve 1.

• Curve 3: Single stage decomposition: This curve is typical of single-stage decomposition temperatures having T_i and T_f.