Search results for "Materiali"

Hedysarum coronarium-Based Green Composites Prepared by Compression Molding and Fused Deposition Modeling

2022

In this work, an innovative green composite was produced by adding Hedysarum coronarium (HC) flour to a starch-based biodegradable polymer (Mater-Bi®, MB). The flour was obtained by grinding together stems, leaves and flowers and subsequently sieving it, selecting a fraction from 75 μm to 300 μm. Four formulations have been produced by compression molding (CM) and fused deposition modeling (FDM) by adding 5%, 10%, 15% and 20% of HC to MB. The influence of filler content on the processability was tested, and rheological, morphological and mechanical properties of composites were also assessed. Through CM, it was possible to obtain easily homogeneous samples with all filler amounts.…

Creep Behavior of Poly(lactic acid) Based Biocomposites

2017

Polymer composites containing natural fibers are receiving growing attention as possible alternatives for composites containing synthetic fibers. The use of biodegradable matrices obtained from renewable sources in replacement for synthetic ones is also increasing. However, only limited information is available about the creep behavior of the obtained composites. In this work, the tensile creep behavior of PLA based composites, containing flax and jute twill weave woven fabrics, produced through compression molding, was investigated. Tensile creep tests were performed at different temperatures (i.e., 40 and 60 °C). The results showed that the creep behavior of the composites is strongly inf…

Toward the Decarbonization of Plastic: Monopolymer Blend of Virgin and Recycled Bio-Based, Biodegradable Polymer.

2022

Decarbonization of plastics is based on two main pillars: bio-based polymers and recycling. Mechanical recycling of biodegradable polymers could improve the social, economic and environmental impact of the use of these materials. In this regard, the aim of this study was to investigate whether concentrations of the same recycled biopolymer could significantly affect the rheological and mechanical properties of biodegradable monopolymer blends. Monopolymer blends are blends made of the same polymers, virgin and recycled. A sample of commercially available biodegradable blend was reprocessed in a single-screw extruder until two extrusion cycles were completed. These samples were exposed to gr…

Surface Modified Arundo Donax Natural Fibers for Oil Spill Recovery

2021

The use of green materials for oil recovery applications is the goal to be achieved to reduce the environmental impact of these essential processes. In this context, Arundo Donax L. is a plant known for its wide uses whose absorbent properties have been previously investigated. In this paper, the influence of silane surface treatment on the absorbent behavior of natural fibers extracted from the culms of this eco-friendly and cost-effective material was assessed. A close correspondence has been identified between the physical characteristics of the investigated oil and the fiber size, by means of microstructural and morphological analysis. Excellent results have been achieved with an absorp…

PLLA-BASED SCAFFOLDS FOR OSTEOCHONDRAL TISSUE REGENERATION VIA THERMALLY INDUCED PHASE SEPARATION TECHNIQUE

L’ingegneria tessutale (TE) è una scienza multidisciplinare che mira a progettare e sviluppare sostituti biologici per migliorare, riparare e/o sostituire i tessuti negli organismi umani. Sulla base della tipica triade dell’ingegneria tessutale è incentrato il primo capitolo Scaffold, Source and Signal; lo scaffold funge da struttura tridimensionale, le cellule rappresentano la source mentre il bioreattore fornisce gli adeguati segnali chimico/fisici. In questo lavoro di tesi sono stati presi in considerazione tutti e tre questi aspetti avendo come obiettivo la rigenerazione osteocondrale. La guarigione dei difetti osteocondrali, riguardanti le lesioni della cartilagine che si esten- dono f…

Contributo per una visione contemporanea dell’azienda agricola: tra sostenibilità e sfide del mondo digitale

2023

Le sfide che l’umanità sta affrontando e da cui dipende la sopravvivenza del pianeta, il diffondersi nell’ambito dell’attività agricola di tecnologie digitali sempre più avanzate e la necessità di adottare un approccio sostenibile che preservi le risorse a tutela delle generazioni future hanno condotto l’azienda agricola a cambiare gradualmente volto. Questo libro mira a contribuire a un’aggiornata riflessione sul ruolo dell’imprenditore agricolo e dell’azienda da lui condotta, osservandone l’organizzazione e composizione alla luce delle regole che oggi la disciplinano e guardando alle innovazioni necessarie a garantire il raggiungimento dei pressanti obiettivi climatici e ambientali verso …

Preparation and characterization of polyolefin- based nanocomposite blown films for agricultural applications

2009

Polyolefin-based films were prepared in the presence of two different organo-modified clays and characterized. The influence of organo-modifier and matrix composition on film morphology and properties were investigated using SEM, XRD, UV-Vis, FT-IR, contact-angle measurements and mechanical tests. The filler increased the films' rigidity and tear strength. Transparencies were almost unchanged in the visible range, but were reduced for harmful radiation. The presence of the clay increases the greenhouse effect, i.e. it hinders the passage of thermal emission from the soil to the outer part of the greenhouse during the night. The wettability of the materials was not influenced by the presence…

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

2018

New calixarene-based nanosponges (CaNSs), i.e., hyper-reticulated polymers constituted by calixarene monomer units joined by means of bis(1,2,3-trialzolyl)alkyl linkers, were synthesized, characterized and subjected to preliminary tests to assess their supramolecular absorption abilities towards a set of suitable organic guests, selected as pollutant models. The synthesis was accomplished by means of a CuAAC reaction between a tetrakis(propargyloxy)calix[4]arene and an alkyl diazide. The formation of the polymeric network was assessed by means of FTIR and 13C{1H} CP-MAS solid-state NMR techniques, whereas morphological characterization was provided by SEM microghaphy. The materials were pro…

Nitrogen-Doped Carbon Nanodots-Ionogels: Preparation, Characterization, and Radical Scavenging Activity

2018

Hybrid diimidazolium-based ionogels were obtained by dispersing nitrogen-doped carbon nanodots (NCNDs) in ionic liquid (IL) solutions and by using dicationic organic salts as gelators. The properties of the NCND-ionogels were studied in terms of thermal stability, mechanical strength, morphology, rheological, and microscopic analyses. Insights into the formation of the hybrid soft material were attained from kinetics of sol-gel phase transition and from estimating the size of the aggregates, obtained from opacity and resonance light-scattering measurements. We demonstrate that, on one hand, NCNDs were able to favor the gel formation both in the presence of gelating and nongelating ILs. On t…

Hydrolytic degradation of PLA/Posidonia Oceanica green composites: A simple model based on starting morpho-chemical properties

2021

Abstract In this work, we studied the degradability of PLA-based biocomposites containing Posidonia Oceanica flour at different loading levels and aspect ratios. Hydrolytic tests were carried out in neutral (pH = 7.4) and alkaline (pH = 10) environment. Time-dependent evolution of some key features, including residual mass and solution uptake, was monitored, and correlated with the changes observed in both morphology and chemical structure of the matrix. The results pointed out that biocomposites degraded much faster than neat PLA in both conditions, up to lose 70% of their initial weight after 1000 h immersion. A complex mechanism was unveiled, evidencing the crucial role of the fillers, c…