Evaluation of Non-isothermal Melt Crystallization Kinetics of the Poly(lactic acid)/Graphene Composites under Variant Cooling Circumstances via Solidification Analysis Approach

The poly(lactic acid) (PLA)/graphene (GN) composites were prepared by solution blending. An in situ measurement technique was adopted to examine the non-isothermal crystallization of PLA/GN composites, which was different from the typical circumstances at constant cooling rate in DSC. The rheological properties of the samples were investigated, and the Carreau-A model was applied to non-linearly fit the rheological data. The non-isothermal crystallization kinetics and solidification behaviors at variant cooling rates were investigated using a modified version of Avrami equation by Jeziorny coupled with three-parameter model (TPM) and four-parameter model (FPM). Our findings showed that the viscosity of the PLA/GN composites dropped with increasing shear rate or GN content. Crystallization kinetic analysis suggested that GN served as an effective nucleating agent for PLA under non-isothermal melt crystallization conditions with variant cooling rate.