Glass in general has many applications for example in daily life (tableware), architecture (windows), art, optics, laboratories, packaging and more. Since every application has different optical, mechanical and thermal requirements and different compositions and production processes can influence these properties, the investigation of glasses is therefore essential.
The investigated sample is an optical glass with a low glass transition (T_g: 496°C) and softening point (T_S: 558°C). The thermal conductivity should be investigated in the temperature range between room temperature and 600 °C.
For that, the thermal diffusivity was determined by LFA 100 and the specific heat capacity by DSC. With the given density, the thermal conductivity can be calculated.
The plot above shows the measured thermal diffusivity and determined thermal conductivity in dependence on temperature. The clear decrease in thermal conductivity between 450 °C and 500 °C and 540 °C and 560 °C, respectively, can be related to the above-mentioned glass transition and softening point.