THz time-domain spectroscopy and imaging of heated commercialized rubber

Rubber has various applications in automobile, household, ducting applications, and other industrial purposes. Commercialized rubbers are now proliferated and accessible to many users. Testing of such kinds of materials is essential for public information about safety and quality assurance. In this work, commercially available rubber sheets were cut into a circular shape. The samples were heated in a vacuum oven from 100 to 200 °C. The THz spectra of the samples were measured using THz Time-Domain Spectroscopy. THz imaging was also done to determine the morphological changes in rubber upon heating. Analysis showed that the THz absorbance of rubber increased with heating temperature. This is attributed to the degradation and physical changes that took place. This was confirmed by the THz images which showed regions of varying densities created due to phase changes within the sample.