The
effect of cooling and compression rates on the tendency to
crystallize/vitrify the canonical glass-forming liquid, propylene
carbonate (PC), was studied by using dielectric spectroscopy. Based
on constructed time–temperature transformation (TTT) and continuous
heating transformation (CHT) diagrams, we have determined the critical
scanning rates that allow avoiding crystallization on cooling from
the liquid state and reheating of the glassy sample, respectively.
In a similar way to isobaric temperature-dependent studies, we have
also carried out isothermal high-pressure measurements upon which
the crystallization tendency of PC was examined as a function of varying
compression and decompression rates (pressures up to 1.3 GPa). We
propose time–pressure transformation (TPT) and continuous decompression
transformation (CDT) diagrams as the pressure analogs of the TTT and
CHT diagrams. Obtained results demonstrate that, qualitatively, one
gets the same picture when pressure (instead of the temperature) is
used as the principal adjustable thermodynamic parameter. In agreement
with this finding, a careful comparison of the time-dependent crystallization
results collected under isobaric and isothermal conditions has revealed
that within the considered T–p range the maximal crystallization rate and dimensionality of the
growing crystals do not depend significantly on whether we vary with
the temperature at a fixed pressure or pressure at a constant temperature.