Search results for " Materiali"
showing 10 items of 710 documents
Effect of graphene nanoplatelets on the photo-oxidative behavior of PP based nanocomposites
2018
The photo-oxidation behavior of polymer nanocomposites depends not only on the photo-oxidation behavior of the matrix, but also on the chemical composition and on the physical properties of the nanoparticles and on the possible interactions between the two phases. Graphene nanoplatelets (GnP) are short stacks of individual layers of graphite that, even at low contents, strongly affects many properties of the thermoplastic matrix. Indeed, by GnP adding, also at low filler concentration (< 5 wt.%), the mechanical, heat-resistance, thermal and electrical properties of the polymer matrix can be surprisingly modified. Of course, the effects of these nanoparticles on the properties of the poly…
Nanocomposites of epoxy resin with graphene nanoplates and exfoliated graphite: Synthesis and electrical properties
2014
Nanocomposites are nowadays one of the most promising materials. Among different fillers, e.g. carbon nanotubes and silicon carbide nanowires (NWSiC), already used with epoxy resin matrices, graphene exfoliated graphite (EG) and graphene nanoplates have some characteristics that make them unique for electromagnetic shielding materials. However, there is still an unresolved problem of proper dispersion that will ensure the homogeneity of samples. To overcome this drawback, inorganic fibres were proposed. An amount of 0.25 phr (parts per hundred; filler content presented as wt.% of the whole polymeric matrix) NWSiC, added to the EG 1 phr/epoxy resin sample, efficiently prevents filler agglome…
Polypropylene/graphene nanoplatelets nanocomposites subjected to elongational flow
2018
In this work the effect of the presence of graphene nanoplatelets (GnP) on the morphology and mechanical properties of polypropylene/GnP nanocomposites has been investigated when these polymer systems are subjected to non-isothermal elongational flow in a melt spinning operation. The presence of the GnP magnifies the effect of the elongational flow. Indeed, the elastic modulus and the tensile strength increases with the orientation more than that observed for the pure matrix.
Photo-oxidative behavior of PP/GnP nanocomposites
2018
In this work the photo-oxidative behavior of neat polypropylene (PP) and PP based nanocomposites incorporating graphene nanoplatelets (GnP) was studied. In particular, the influence of the amount of incorporated GnP was evaluated. The photo-oxidation has been followed by monitoring the change of the rheological, mechanical and spectroscopic properties upon artificial exposure to UV-B light. The results revealed that the presence of GnP reduced the rate of photooxidation of the PP matrix and, in the investigated composition range, the photo-stabilizing action improved with increasing the GnP content.
Effect of Different Matrices and Nanofillers on the Rheological Behavior of Polymer-Clay Nanocomposites
2010
In this work, a comprehensive study of the rheologi-cal behavior under shear and isothermal and nonisothermal elongational flow of low density polyethylene (LDPE) and ethylene-vinyl acetate copolymer (EVA) based nanocomposites was reported to evaluate their "filmability", that is, the ability of these material to be processed for film forming applications. The influence of two different kinds of organoclay - namely Cloisite 15A and Cloisite 30B - and their concentration was evaluated. The presence of filler clearly affects the rheological behavior in oscil-latory state of polyolefin-based nanocomposites but the increase of complex viscosity and the shear thinning are not dramatic. A larger …