Structure reorganization of the glass of polyamide 6 (PA 6) was investigated by fast scanning chip calorimetry (FSC). The melt was vitrified by fast cooling, and then the glass was annealed as a function of temperature and time. During annealing, there is first observed classical enthalpy relaxation, and only after its completion there is detected homogeneous crystal nucleation followed by crystal growth. The kinetics of the various processes was determined from subsequently recorded FSC heating scans. The analysis of structure reorganization covering a time scale of seven orders of magnitude allowed separation of the individual relaxation/ordering processes to gain new information about the interplay between enthalpy relaxation, nucleation and crystal growth and related changes of the mobility of the amorphous phase/formation of a rigid amorphous fraction. The collected data reveal that nuclei formation is only observed if the enthalpy relaxation of the glass is completed. It is suggested that a prerequisite for nuclei formation is a prior densification of the glass, supporting the assumption of a homogeneous nucleation mechanism.

Sequence of enthalpy relaxation, homogeneous crystal nucleation and crystal growth in the glass of polyamide 6

247th National Meeting (2014)

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