1. “…. a technique in which the mass of a substance is measured as a function of temperature, while the substance is subjected to a controlled temperature programme.” “Controlled temperature programme” can mean: heating and/or cooling at a linear rate (by far commonest) isothermal measurements combinations of heating, cooling and isothermal stages other, more modern approaches, in which the temperature profile is modified according to the behaviour of the sample.

2. GAS-TIGHT ENCLOSURE SAMPLE HEATER TEMPERATURE PROGRAMMER BALANCE CONTROLLER POWER FURNACE TEMP. SAMPLE TEMP. WEIGHT GAS IN

4. Mass (%) in green, rate of mass loss (%/°C) in blue.

5. CONVECTION THROUGH SURROUNDING ATMOSPHERE CONDUCTION THROUGH SAMPLE PAN AND INSTRUMENT RADIATION FROM FURNACE WALL EXCHANGE OF GASES: REACTING GASES IN, PRODUCTS OUT INDICATION OF SAMPLE TEMPERATURE

6. A) INSTRUMENTAL heating rate furnace atmosphere and flow-rate geometry of pan and furnace material of pan B) SAMPLE-RELATED mass particle size sample history/pre-treatment packing thermal conductivity heat of reaction For a given instrument, careful standardisation of experimental procedures leads to highly reproducible results.

7. 10 mg samples of PTFE, heated at 2.5, 5, 10 and 20 °C/min in nitrogen

10. CaC 2 CO 4.H 2 O in air and nitrogen

11. A) MASS Classical buoyancy Effect temp. on balance convection and/or turbulence viscous drag on suspension B) TEMPERATURE Temperature calibration difficult to carry out accurately. Many methods exist, but none totally satisfactory. Best accuracy from simultaneous TG-DTA or TG-DSC instrument. These are lumped together as the “buoyancy” correction, and if significant, can be allowed for by a blank run NOISY OR ERRATIC RECORDS CAN ARISE FROM: static vibration pressure pulses in lab. uneven gas flow

12. a = PVC, b= nylon-6, c = LDPE, d= PTFE

19. PROCESSWEIGHT GAINWEIGHT LOSS Ad- or absorption Desorption, drying Dehydration, desolvation Sublimation Vaporisation Decomposition Solid-solid reactions (some) Solid-gas reactions Magnetic transitions

20. D. M. Price, D. J. Hourston & F. Dumont, “Thermogravimetry of Polymers”, R. A. Meyers (Ed.), Encyclopedia of Analytical Chemistry, John Wiley & Sons Ltd., Chichester (2000) pp. 8094-8105. G. R. Heal, “Thermogravimetry & Derivative Thermogravimetry”, in P.J. Haines (ed.) Principles of Thermal Analysis & Calorimetry, ch. 4, Royal Society of Chemistry, Cambridge (2002) pp. 10-54. C. M. Earnest (Ed.), Compostional Analysis by Thermogravimetry, ASTM STP 97, American Society for Testing and Materials (1988).