Thermally stimulated luminescence and conductivity — Additional tools for thermal analysis of polymers

Abstract

The physical phenomena underlying thermally stimulated luminescence and conductivity measurements, logically considered as complementary to conventional thermal analysis measurements, are outlined. The equipment and samples required to make such measurements are briefly described, and the basic concepts underpinning the interpretation of the data sketched. Some recent experimental data, chosen to reflect the sensitivity of thermally stimulated luminescence and conductivity to doping of the sample and changes in its morphology, are presented and discussed.The application of thermal analysis techniques to the study of organic polymers has increased rapidly in recent years [1,2]. The range of information which can be extracted from such measurements is impressive, e.g. glass transition, crystallization and melting temperatures, the effects of additives such as plasticizers and stabilizers on these parameters, thermal stability, degree of curing, and possibly identification of the components in a polymer mixture.

Analysis of the luminescence decay following excitation of polyethylene naphthalate films by an electric field

“…Thermal detrapping of carriers and subsequent recombination explain the thermoluminescence curve observed on subsequent warming, the emission occurring at temperatures characteristic of the material [9][10][11].…”

Charge trap spectroscopy in polymer dielectrics: a critical review

“…Up to now, though some works report on the quenching effects for inorganics [140] it seems not to have been considered in the literature on TL in polymers. It is probably due to the fact that wavelength-resolved spectra have been reported scarcely [186,187], such that little was known about the origin of the emission. As we have shown that the luminescence involved in TL is phosphorescence, and that the phosphorescence itself varies strongly with temperature because of quenching effects, there is no reason to consider that the quantum efficiency of TL is not dependent on the temperature.…”

A comparative study of radiation effects in medical-grade polymers: UHMWPE, PCU and PEEK

“…TSL is routinely used in radiation dosimetry and for archeological dating. It has also been used extensively to study radiation effects on polymers (Partridge, 1972(Partridge, , 1982Charlesby and Partridge, 1965;Fleming and Hagekyriakou, 1984;Fleming, 1990). Sahare and others (1992) observed a correlation between TSL intensity and the draw ratio of gamma-irradiated co-extruded PEEK fibers.…”