PHASE-TRANSITION STUDIES IN N-ALKANES AND PETROLEUM-RELATED WAXES - AREVIEW

A review is presented concerning the application of various analytical methods, viz. differential thermal analysis (DTA), differential scann ing calorimetry (DSC), dilatometry, infrared spectroscopy, X-ray diffr actometry, nuclear magnetic resonance spectrometry, electron diffracti on and scanning tunneling microscopy for the investigation of solid-so lid phase transition phenomenon in pure n-alkanes, their binary mixtur es and petroleum (both paraffinic and microcrystalline) and related wa xes. Particular attention has been paid to the phase transition mechan isms that can be revealed by different methods involving changes in co mplex molecular motions with temperature in petroleum waxes with empha sis on the similarities and deviations from n-alkanes. Pressure-induce d phase-transitions are also discussed. Some of the possible future ap plications of this study have been outlined.