During his PhD study on polymers, adiabatic calorimetry was at the basis of Bernhard Wunderlich's research activities. Since then he applied quantitative calorimetry in all its different forms. The use of 2- or 3 state models for describing the heat capacity in terms of mass fractions of crystalline and amorphous parts of the material studied, necessitated the knowledge of the heat capacities of fully crystalline and fully amorphous polymers. Consequently, the ATHAS Databank was started which is still up to date.The successful determination of the temperature dependencies of thermodynamic quantities like Cp, enthalpy, entropy and Gibbs free energy of more than 200 polymers facilitated many related studies by researchers world wide. It enabled, for instance, the determination of crystallinity as a function of temperature, and of the baseline and excess heat capacities. The latter is the necessary link to theory, as for example MC simulations of crystallization and morphology. In addition, the free energy data obtained provided realistic driving forces for crystallization. Nowadays these are to be preferred instead of using outdated approximations. This is especially relevant for research at high supercoolings, as these can be realized nowadays by fast scanning calorimetry (FSC).In all the work he kept emphasizing that polymers show appreciable reorganization effects as caused by metastability of crystallites. Therefore, efforts were taken to increase the understanding of processes like supercooling, amorphization, hot and cold crystallization; recrystallization and remelting; annealing. Besides the aim of mimicking scanning rates as in processing and in practice, also remedies for reorganization effects were sought which stimulated the development of specific instrumentation like FSC .Being an excellent educator his support stimulated many young researchers. His continuously updated thermal analysis course was highly valued as were his books .In the lecture the topics mentioned will be discussed using state-of-the-art results.

Bernhard Wunderlich: A pioneer in crystallization, thermal analysis and calorimetry

247th National Meeting (2014)

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