Something about amber: Fictive temperature and glass transition temperature of extremely old glasses from copal to Triassic amber

In previous work we successfully used a stable Dominican amber to investigate the sub-glass transition dynamics of an organic glass with extremely low fictive temperature. The results provided an incentive to seek other stable ambers with lower values of fictive temperature. In the present work, a series of fossil resins from different locations, and ages ranging from approximately 100 years–230 million years, has been investigated using differential scanning calorimetry. The measurement results show the thermal signatures for each fossil sample: copals are unstable, and have lower glass transition temperatures than the amber samples. For the amber samples, there is not a systematic age dependence for the amberʹs glass transition temperature. Furthermore, even for the same sort of amber, the thermal properties can be different for different samples. The stability of the fossil resins was studied and glass transition temperatures were determined. For the stable samples, fictive temperature was also determined.