0000000000279072
AUTHOR
M. Ceraulo
Morphology and properties of compatibilized PP/PET melt spun fibers
This work provides a study on the influence of a rubbery compatibilizer on the morphology and on the physical properties of polypropylene (PP)/polyethylenetherephthalate(PET) melt spun fibers at different hot draw ratios. In particular, a sample of SEBS copolymer grafted with maleic anhydride was used as compatibilizer. Both the uncompatibilized PP/PET blend and the compatibilized one were prepared by melt compounding in a counter-rotating twin-screw extruder. The materials have been characterized from a rheological, morphological and mechanical point of view. The addition of the compatibilizer increased the viscosity in shear flow of the uncompatibilized blend, and significantly improved t…
Non-isothermal elongational flow of polymer nanocomposites
The elongational flow is a very important flow involved in important processing operations, like spinning, film blowing, etc. In these processing operations, the molten polymer is subject to the elongational flow and at the same time is cooled (non-isothermal elongational flow). The response to the non-isothermal elongational flow of the melt is then the critical parameter to process the polymer in these processing operations. MS (melt strength) and BSR (breaking stretching ratio) are to two values measured during the non-isothermal flow and depend mainly on the molecular structure of the polymer. In biphasic systems, the adhesion and the shape of the dispersed particles play a very importa…
Thermomechanical degradation of PLA-based nanobiocomposite
Nanobiocomposites are a new class of biodegradable polymer materials with nanometric dispersion of inert particles in a biodegradable polymer matrix that show very interesting properties often very different from those of conventional- filled polymers and also biodegradability. An important issue in the applications of the biodegradable polymers is their easy degradability during processing due to the thermomechanical stress or to the presence of humidity. In this work, the thermomechanical degradation behavior of a nanobiocomposite made by a PLA-based blend and an organomodified montmorillonite has been investigated. The degradation kinetics has been followed by means of rheological, mecha…
Photo-oxidative behavior of PP/GnP nanocomposites
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 graphene nanoplatelets on the photo-oxidative behavior of PP based nanocomposites
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…
Effetto del flusso elongazionale su nanocompositi a base di miscele polimeriche.
Scopo di questo lavoro è stato, pertanto, quello di studiare l’effetto del flusso elongazionale su nanocompositi a base di miscele poliammide/polietilene al fine di valutare come questo possa influenzare e modificare le principali proprietà. In particolare, si è osservato come variano le proprietà meccaniche fra il materiale isotropo (piastrine ottenute per stampaggio a compressione) e il materiale orientato ottenuto per filmatura in bolla.
Thermomechanical degradation of PP based nanocomposites filled with graphene nanoplatelets
Graphitic nanofillers have extensively used to prepare nanocomposites based on both conventional petroleum based plastics and bio-based polymers . Among them, graphene or graphite nanoplatelets (GnP), also called graphite nanosheets or nanoflakes, are a relatively new carbon nanomaterial composed of stacked 2D graphene sheets with outstanding electrical, thermal and mechanical properties. Indeed, by adding GnP, also at low filler concentration (< 5 wt.%), the mechanical, heat-resistance, thermal and electrical properties of the polymer matrix can surprisingly enhance due to unique properties of these nanofillers. However, the characteristics of these multiphase systems certainly depend o…
Polypropylene/graphene nanoplatelets nanocomposites subjected to elongational flow
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.