Morphology, Rheological and Mechanical Properties of Isotropic and Anisotropic PP/rPET/GnP Nanocomposite Samples

Abstract

The effect of graphene nanoplatelets (GnPs) on the morphology, rheological, and mechanical properties of isotropic and anisotropic polypropylene (PP)/recycled polyethylene terephthalate (rPET)-based nanocomposite are reported. All the samples were prepared by melt mixing. PP/rPET and PP/rPET/GnP isotropic sheets were prepared by compression molding, whereas the anisotropic fibers were spun using a drawing module of a capillary viscometer. The results obtained showed that the viscosity of the blend is reduced by the presence of GnP due to the lubricating effect of the graphene platelets. However, the Cox–Merz rule is not respected. Compared to the PP/rPET blend, the GnP led to a slight increase in the elastic modulus. However, it causes a slight decrease in elongation at break. Morphological analysis revealed a poor adhesion between the PP and PET phases. Moreover, GnPs distribute around the droplets of the PET phase with a honey-like appearance. Finally, the effect of the orientation on both systems gives rise not only to fibers with higher modulus values, but also with high deformability and a fibrillar morphology of the dispersed PET phase. A fragile-ductile transition driven by the orientation was observed in both systems.

Melt processing behaviour and structure development in recycled PP blends with recycled PET

“…The decrease of viscosity of polymer melt containing additives is reported before especially for fibers when oriented along the flow direction as well as for nano additives. 25 A few authors have reported in the past that the oriented short fibers in the polymer melt lead to reduction of the viscosity during processing. Nishitani and Kitano 26 observed decrease in viscosity of polyamide by addition of 1% of carbon nanofiber at all shear rates.…”

“…Vaxman et al 28 conclude that the orientation of fiber in the direction of flow leads to decrease in melt viscosity. Francesco et al 29 reported that the melt viscosity measured by capillary rheometer in PP-rPET blend decreased by addition of 2% nanoparticle. In the present case, it is contented that the addition of R-PET above the critical concentration leads to nano-fiber formation of the dispersed phase and hence reduction in melt viscosity of the blend.…”

Analysis on Isotropic and Anisotropic Samples of Polypropylene/Polyethyleneterephthalate Blend/Graphene Nanoplatelets Nanocomposites: Effects of a Rubbery Compatibilizer

“…The main materials used in this work are as follows: [23]: average diameter between 1 and 2 µm; an average thickness lower than 2 nm; and a specific surface area of about 750 m 2 /g.…”

“…The drawing ratio, DR, of the fibers was computed, following the methodology detailed in a prior study [23], using the following formula:…”

Crystallisation Kinetics and Associated Electrical Conductivity Dynamics of Poly(Ethylene Vinyl Acetate) Nanocomposites in the Melt State

“…GNPs consist of two-dimensional graphite layers, and modern preparation methods can ensure thicknesses that range from one to several atoms [ 1 , 2 , 3 ]. Consequently, they possess very interesting electrical [ 7 , 8 , 9 , 10 , 11 , 12 ], mechanical [ 12 , 13 , 14 ] and rheological [ 15 , 16 , 17 ] properties. The incorporation of such carbonaceous fillers in a polymer matrix leads to some degree of electrical conductivity, with the resulting system exhibiting a percolation-type of behaviour [ 18 , 19 , 20 , 21 , 22 ].…”