Isothermal Crystallization Kinetics of In Situ Nylon 6/Graphene. Composites by Differential Scanning Calorimetry
writer：Fan Zhang, Bo Wang, Ruilin Man, Zhiyuan Peng
keywords：nylon 6, graphene, composites, isothermal crystallization, kinetics, differential scanning calorimetry (DSC)
source：期刊
specific source：Polymer Engineering and Science
Issue time：2013年
The isothermal crystallization kinetics of nylon 6/graphene
(NG) composites prepared by in situ polymerization was investigated by
differential scanning calorimetry. The Avrami equation was used to study the
crystallization kinetics. Comparing with nylon 6, it is found that the NG composites
(NG-0.1, NG-0.5 and NG-1.0, where the number describes the wt% content of graphene)
had higher crystallization rates; the crystallization rate increased remarkably
with 0.1wt% graphene. However, too many crystallization nuclei could not
accelerate the crystallization process effectively. The tmax values
obtained from the plots of heat
flow versus time were in agreement with the tmax values calculated from the half time of
crystallization when the graphene content was
lower than 1.0 wt%, which means that the values of the Avrami parameters calculated from the half time of
crystallization might be in better agreement
with the actual crystallization mechanism than that determined from the Avrami
plots. The n values of the NG composites ranged between 1.1 and 1.8, which can be interpreted as
meaning 1-dimensional crystallization growth occurred during isothermal
crystallization process. The activation energies, which were determined by the Arrhenius’
method, varied within the range from -188 ~ -142kJ/mol. In comparison with
nylon 6, the activation energies of the NG composites decreased obviously with 0.1wt%
of graphene.