TABLE OF CONTENTS Thermal analysis includes a group of techniques in which specific physical properties of a material are measured as a function of temperature. The techniques include the measurement of temperatures at which changes may occur, the measurement of the energy absorbed ( endothermic transition) or evolved ( exothermic transition) during a phase transition or a chemical reaction, and the assessment of physical changes resulting from changes in temperature.
Various environments (vacuum, inert, or controlled gas composition) and heating rates from 0.1 to 500 C min ?1 are available for temperatures ranging from ?190 to 1400 C. The analysis of gas(es) released by the specimen as a function of temperature is possible when thermal analysis equipment is coupled with Fourier-transform infrared detection or with a mass spectrometer.
The applications of thermal analysis are many and varied. For environmental measurements, these parameters can be measured: vapor pressure, thermal stability, flammability, softening temperatures, and boiling points. Compositional analysis offers phase diagrams, free versus bound water, solvent retention, additive analysis, mineral characterization, and polymer system analysis. In the important area of product reliability, thermal methods provide heat-capacity data, liquid-crystal transitions, solid fat index, purity, polymer cures, polymer quality control, glass transitions, Curie point, and fiber properties. Information on stability can be obtained from modulus changes, creep studies, expansion coefficients, and antioxidant evaluation. Dynamic properties of materials are found from viscoelastic measurements, impact resistance, cure characteristics, elastic modulus, loss modulus, and shear modulus. Lastly, chemical reactions can be followed through heats of...
