Thermal analysis-TG-DTA

It is the slide prepared by me to explain TG -DTA in short in SAC-7 seminar , at manuguru AP.

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, B angalore

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 volume Dilatometry

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 (N 2 or 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 CaCO 3 at different gas atmosphere Effect of gas atmosphere and crucible on TG Decomposition of CaCO 3 using different crucible

10. Three factors should be noted when you get a TG curve: General shape. The particular T at which changes in mass occur. 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 =T S - T r 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 industry Food 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 ̊ C Rhombohedral to monoclinic 124 ̊C Melting point 179 ̊C Liquid phase transistion ̊C Boiling point Sulfur element

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

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