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 t_max values obtained from the plots of heat flow versus time were in agreement with the t_max 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.