Non-isothermal crystallization kinetics of polyamide-6/graphite oxide nanocomposites

Polyamide-6 (PA6)/graphite oxide (GO) nanocomposite was synthesized using delamination/absorption with dimethylacetamide as solvent. TEM showed that graphite oxide sheets were completely exfoliated and distributed uniformly in polyamide-6 matrix. Non-isothermal crystallization behaviors of PA6 and nanocomposites were investigated using DSC. The modified Avrami, Mo and Ozawa equation were employed to investigate the crystallization process. The former two could successfully describe the non-isothermal crystallization of PA6 and nanocomposites. It was interesting to find that Ozawa equation could successfully describe the non-isothermal crystallization of nanocomposites, but it was not valid for PA6. The crystallization rate of nanocomposites greatly decreased by the addition of GO, which confirmed by the results of half-time of crystallization (t1/2), crystallization rate exponent Zc and log F(T). Also, the more the content of GO, the slower the crystallization rate. The effective activation energy calculated from Friedman formula suggested that the layered structure of GO restrained the crystallization of PA6.