THERMODYNAMIC PROPERTIES OF CYCLOKETONES - A DSC STUDY

In this paper, we describe the study of the thermodynamic properties o f all cycloketones, from cyclobutanone to cyclododecanone, through DSC measurements in order to reveal possible new glassy crystalline phase s. This work presents revised phase diagrams of the four previously kn own plastic crystals of the series, namely cyclohexanone, cycloheptano ne, cyclooctanone, and cyclononanone. In particular, it has been shown that the last three crystals exhibit two phase sequences, a stable on e and a metastable one, which could be attained through reproducible h eat treatments. Contrary to what could be expected by comparison with the cyclo-alcohol series, only two compounds, namely cyclooctanone and cyclononanone, exhibit glassy crystalline phases. Finally, the thermo dynamic data related to the various phase transitions of all these com pounds have been determined. (C) 1998 Elsevier Science B.V.