Ricerc@Sapienza

La cristallizzazione da fuso del polipropilene isotattico è stata studiata in condizioni dinamiche mediante un’implementazione dell’FTIR a temperatura variabile. Per questo scopo, gli spettri sono acquisiti sequenzialmente durante un programma di temperatura che prevede una rampa di raffreddamento lineare con sovrimposta una funzione periodica (Temperature Modulated FTIR, TMFTIR).

This study deals with the development and optimization of hybrid composites integrating microcrystalline cellulose and short basalt fibers in a polypropylene (PP) matrix to maximize the mechanical properties of resulting composites. To this aim, the effects of two different coupling agents, endowed with maleic anhydride (MA-g(grafted)-PP) and acrylic acid (AA-g-PP) functionalities, on the composite properties were investigated as a function of their amount.

In order to investigate the role of plant hybridization in barley on the overall thermomechanical performance of polymeric composites containing their by-products, straws from one self-pollinated (Quench) and two F1 hybrid lines of barley (Tatoo and Zoo) were collected and characterized from the chemical (FTIR), structural (XRD), thermal (TGA) and mechanical (tensile) point of view, and used as reinforcements in a commodity plastic, such as polypropylene.

In the present study, we report about the influence of an external permanent magnetic field on electrical resistivity and dielectric permittivity of PP + Fe3O4 and PVDF + Fe3O4 based nanocomposites. It was found that independent of the type of polymer the electric resistivity of both polymer nanocomposites decreases under the influence of a magnetic field and the negative magnitoresistive effect has been observed. Investigation of MR in PP + Fe3O4 and PVDF + Fe3O4 based nanocomposites showed that at room temperature the concentration dependence of MR is identical for both systems.

Structure and dielectric properties of polymer nanocomposites based on isotactic polypropylene and iron oxide
(Fe3O4) nanoparticles are studied. Distribution of magnetite nanoparticles in a polymer matrix was studied by
scanning electron microscopy (SEM, Carl Zeiss). Dielectric properties of nanocomposites were examined by
means of E7-21 impedance spectrometer in the frequency range of 102–106 Hz and temperature interval of
298–433 K. The frequency and temperature dependences of the dielectric permittivity ε, as well as the

In this study, we report about the preparation of magnetic polymer nanocomposites on the basis of isotactic polypropylene and magnetite Fe3O4 nanoparticles. The structure and composition of polymer nanocomposite materials have been studied by scanning electron microscopy, atomic force microscopy, and X-ray dispersive analysis. The magnetic properties of polymer nanocomposites based on PP+Fe3O4have been investigated.

In the present study, the influence of the temperature–time mode of crystallization (TTC) on the morphology and thermal properties of PP/Fe3O4 nanocomposite materials was investigated. The morphology of the nanocomposites prepared in different TTC mode was studied by atomic force microscope. AFM study shows that the root mean square roughness of samples is 90–95, 50, 21 nm for PP/Fe3O4@20, PP/Fe3O4@200 and PP/Fe3O4@20000 respectively. Thermo gravimetric analysis was employed to investigate the thermal stability of PP/Fe3O4 nanocomposites obtained applying different TTC modes.