1. Terry A. Ring Chemical Engineering University of Utah
Thermal Analysis
Terry A. Ring
Chemical Engineering
University of Utah

2. Different Techniques Thermometric Titration (TT)
Heat of mixing
Thermal Mechanical Analysis (TMA)
Thermal Expansion Coefficient
Dynamic Mechanical Analysis (DMA)
Viscoelastic Properties
Differential Scanning Calorimetric (DSC)
Heat flow during Transitions
Thermal Gravimetric Analysis (TGA)
Weight Loss due to decomposition
Derivative Thermogravimetric Analysis (DTG)
Differential Thermal Analysis (DTA)
Heat of Transitions
Temperature Programmed Desorption (TPD)
Temperature at which gas is desorbed from (catalyst) surface
Emission gas Thermoanalysis (EGT)

3. Basic Principle Sample is heated at a constant heating rate
Sample’s Property Measured
Wt TGA
Size TMA
Heat Flow DSC
Temp DTA
Gas evolved TPD

4. TGA Constant Heating Rate Data Differential This Data (DTG)
Initial Temp
Final Temp
Heating Rate (°C/min)
Data
Weight vs Time
Weight vs Temp.
Differential This Data (DTG)

5. DSC

6. DSC Constant Heating Rate Data Measures heat of crystallization
Initial Temp
Final Temp
Heating Rate (°C/min)
Data
Heat flow to sample minus Heat flow to reference vs Time (Temp.)
Measures heat of crystallization
Polymer without weight change in this temperature range

7. DTA Sample and Reference Placed in Heater Constant Heating Rate Data
Initial Temp
Final Temp
Heating Rate (°C/min)
Data
Temp of Sample vs Time (or Temp)
Temp of Reference vs Time (or Temp)
Reference should be inert, e.g. nothing but latent heat
Measures
Heat of crystallization
Glass Transition Temperature

8. DTA + DTG

9. TMA Constant Heating Rate Data Measures Initial Temp Final Temp
Heating Rate (°C/min)
Data
Size of Sample vs Time (or Temp.)
Measures
Thermal Expansion Coefficient
Volume change on crystalization or crystal transformations
Sintering
Glass Transitions in Polymers

10. TMA
Polymer with glass transition

11. DMA Constant Heating Rate Data Measures Initial Temp Final Temp
Heating Rate (°C/min)
Data
Force vs Time (or Temp.)
Force delay vs Time (or Temp.)
Viscoelastic Properties
Storage and Loss Modulus
Measures
Glass Transition
Polymer with Glass Transition

12. We have TGA - only Heating a sample of Calcium oxalate
Ca(C204)*xH2O  Ca(C204) *H2O + x-1 H2O
Ca(C204)*H2O Ca(C204) + H2O
Ca(C204)  CaCO3 + CO
CaCO3  CaO + CO2

13. TGA Constant Heating Rate Data Differential This Data (DTG)
Initial Temp
Final Temp
Heating Rate (°C/min)
Data
Weight vs Time
Weight vs Temp.
Differential This Data (DTG)

14. TGA – Ca(C204)*xH2O

15. Different Heating Rates

16. Heating Rate Heating Too Fast Interpretation Problems
Overlaps Transitions
Interpretation Problems
Kinetics of Decomposition
Sample Size
Mass Transfer
Convective Mass Transfer
Pore Diffusion
Heat Transfer
Convective Heat Transfer
Thermal Conductivity
Porous solid

17. Precipitated Zr5O8(SO4)2*15 H2O
This sample was dried fro 48 hrs at 110C before TGA analysis.
What is going on?

18. Analysis of Filtrate from Precipitation
5ZrOCl2 + 2H2SO4 + xH2O  Zr5O8(SO4)2*15 H2O (s) + 10 HCl
Decomposition
Zr5O8(SO4)2*15 H2O (s)  Zr5O8(SO4)2*14 H2O (s) + H2O (v)
Zr5O8(SO4)2  ZrO2 (s) +2 SO2 (v)