Browsing by Keyword "Composites"
Now showing 1 - 8 of 8
Results Per Page
Sort Options
Item Additive Manufactured Scaffolds for Bone Tissue Engineering: Physical Characterization of Thermoplastic Composites with Functional Fillers: Physical Characterization of Thermoplastic Composites with Functional Fillers(2021-08-13) Sinha, Ravi; Sanchez, Alberto; Camara-Torres, Maria; Uriszar-Aldaca, Iñigo Calderon; Calore, Andrea Roberto; Harings, Jules; Gambardella, Ambra; Ciccarelli, Lucia; Vanzanella, Veronica; Sisani, Michele; Scatto, Marco; Wendelbo, Rune; Perez, Sergio; Villanueva, Sara; Matanza, Amaia; Patelli, Alessandro; Grizzuti, Nino; Mota, Carlos; Moroni, Lorenzo; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓN; Tecnalia Research & InnovationThermoplastic polymer–filler composites are excellent materials for bone tissue engineering (TE) scaffolds, combining the functionality of fillers with suitable load-bearing ability, biodegradability, and additive manufacturing (AM) compatibility of the polymer. Two key determinants of their utility are their rheological behavior in the molten state, determining AM processability and their mechanical load-bearing properties. We report here the characterization of both these physical properties for four bone TE relevant composite formulations with poly(ethylene oxide terephthalate)/poly(butylene terephthalate (PEOT/PBT) as a base polymer, which is often used to fabricate TE scaffolds. The fillers used were reduced graphene oxide (rGO), hydroxyapatite (HA), gentamicin intercalated in zirconium phosphate (ZrP-GTM) and ciprofloxacin intercalated in MgAl layered double hydroxide (MgAl-CFX). The rheological assessment showed that generally the viscous behavior dominated the elastic behavior (G″ > G′) for the studied composites, at empirically determined extrusion temperatures. Coupled rheological–thermal characterization of ZrP-GTM and HA composites showed that the fillers increased the solidification temperatures of the polymer melts during cooling. Both these findings have implications for the required extrusion temperatures and bonding between layers. Mechanical tests showed that the fillers generally not only made the polymer stiffer but more brittle in proportion to the filler fractions. Furthermore, the elastic moduli of scaffolds did not directly correlate with the corresponding bulk material properties, implying composite-specific AM processing effects on the mechanical properties. Finally, we show computational models to predict multimaterial scaffold elastic moduli using measured single material scaffold and bulk moduli. The reported characterizations are essential for assessing the AM processability and ultimately the suitability of the manufactured scaffolds for the envisioned bone regeneration application.Item Bioplastics and Carbon-Based Sustainable Materials, Components, and Devices: Toward Green Electronics: Toward Green Electronics(2021-10-20) Bozó, Éva; Ervasti, Henri; Halonen, Niina; Shokouh, Seyed Hossein Hosseini; Tolvanen, Jarkko; Pitkänen, Olli; Järvinen, Topias; Pálvölgyi, Petra S.; Szamosvölgyi, Ákos; Sápi, András; Konya, Zoltan; Zaccone, Marta; Montalbano, Luana; De Brauwer, Laurens; Nair, Rakesh; Martínez-Nogués, Vanesa; San Vicente Laurent, Leire; Dietrich, Thomas; Fernández de Castro, Laura; Kordas, Krisztian; Tecnalia Research & Innovation; Alimentación SostenibleThe continuously growing number of short-life electronics equipment inherently results in a massive amount of problematic waste, which poses risks of environmental pollution, endangers human health, and causes socioeconomic problems. Hence, to mitigate these negative impacts, it is our common interest to substitute conventional materials (polymers and metals) used in electronics devices with their environmentally benign renewable counterparts, wherever possible, while considering the aspects of functionality, manufacturability, and cost. To support such an effort, in this study, we explore the use of biodegradable bioplastics, such as polylactic acid (PLA), its blends with polyhydroxybutyrate (PHB) and composites with pyrolyzed lignin (PL), and multiwalled carbon nanotubes (MWCNTs), in conjunction with processes typical in the fabrication of electronics components, including plasma treatment, dip coating, inkjet and screen printing, as well as hot mixing, extrusion, and molding. We show that after a short argon plasma treatment of the surface of hot-blown PLA-PHB blend films, percolating networks of single-walled carbon nanotubes (SWCNTs) having sheet resistance well below 1 kω/□ can be deposited by dip coating to make electrode plates of capacitive touch sensors. We also demonstrate that the bioplastic films, as flexible dielectric substrates, are suitable for depositing conductive micropatterns of SWCNTs and Ag (1 kω/□ and 1 ω/□, respectively) by means of inkjet and screen printing, with potential in printed circuit board applications. In addition, we exemplify compounded and molded composites of PLA with PL and MWCNTs as excellent candidates for electromagnetic interference shielding materials in the K-band radio frequencies (18.0-26.5 GHz) with shielding effectiveness of up to 40 and 46 dB, respectively.Item A Concrete and Viable Example of Multimaterial Body: The Evolution Project Main Outcomes: The Evolution Project Main Outcomes(2017) Cischino, Elena; Vuluga, Zina; Elizetxea, Cristina; Benito, Iratxe Lopez; Mangino, Enrico; de Claville Christiansen, Jesper; Sanporean, Catalina-Gabriela; Di Paolo, Francesca; Kirpluks, Mikelis; Cābulis, Pēteris; Ezeiza, Cristina Elizetxea; Cabulis, Pěteris; POLIMEROSFunded by the EC FP7 Programme, EVolution project demonstrated that it is possible to consistently reduce the vehicle weight through the wide use of new materials and process technologies, mainly by developing a multi-material Body-in-White. This paper focuses on three of the five structural body demonstrators, the main objective of the framework, strongly hybridized with aluminum and thermoplastic composite materials, specifically developed and manufactured through innovative technologies. Directing in particular the analysis on medium production volumes (> 30,000 units/year), the industrial viability is evaluated in terms of TAKT time, lightweighting costs, weight reduction and structural performances achieved.Item Effect of the biobased polyols chemical structure on high performance thermoset polyurethane properties(2022-12-16) Echeverria-Altuna, O.; Ollo, O.; Larraza, I.; Gabilondo, N.; Harismendy, I.; Eceiza, A.; POLIMEROS; Tecnalia Research & InnovationThe sustainability of the polymeric materials has become a fundamental challenge; therefore, the development of new biobased formulations has gained increasing interest. Thermoset polyurethanes (PURs) present high performance and are a competitive solution for structural composites. However, polyols used in the PUR synthesis are typically from petrochemical origin. Nowdays, a broad range of biobased polyols is available in the market, but there is not yet a specific formulation for high performance PURs composites. The aim of this work was to study the effect of biobased polyols' characteristics in the PUR processing and final properties. In addition, biobased polyol features to synthesize BIO-PURs suitable for structural applications were stablished. The viscosity and reactivity were studied by means of rheology and differential scanning calorimetry (DSC). Thermal and mechanical properties were studied through thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and flexural tests. The results obtained demonstrated the dramatic influence of polyols’ nature on BIO-PUR/PUR properties and their effect on the crosslink density. It was observed that using a high functionality and high hydroxyl index biobased polyol, it was possible to synthesize high performance BIO-PUR suitable for structural composites.Item Evolution FP7 funded project: body structure design strategies using new composite and aluminium materials and enabled technologies(InderScience, 2018-04-20) Mangino, Enrico; Alcalde, Estibaliz; Maestro, César; Di Paolo, Francesca; DeClaville Christiansen, Jesper; Sanporean, Catalina Gabriela; Deverill, John P.; Cischino, Elena; Elizetxea, Cristina; Lopez, Iratxe; Vuluga, Zina; Kirpluks, Mikelis; Cabulis, PeterisBased on Pininfarina Nido EV concept, EVolution aims to reduce the vehicle weight through new materials and process technologies, focused on five demonstrators: underbody, front crossbeam, mechanical subframe, shotgun system and door. This paper refers to body structure design strategies using new composite, Al materials and enabled technologies, focusing in particular on demonstrators design and manufacturing. The new front crossbeam geometry of the front shell is adapted starting from the Nanotough design, while the rear shell is specific for EVolution. The subframe demonstrator is redesigned to fulfil mechanical requirements of the part and manufacturing feasibility either. The EVolution door concept consists of two semistructural composite skins including a structural Al frame. The underbody is conceived through an integrated approach, optimising each element for its function. The shotgun component is designed to link parts obtained with different manufacturing technologies and several aluminium alloys in one single component: the structural node demonstrator.Item Fabrication and characterisation of Titanium Matrix Composites obtained using a combination of Self propagating High temperature Synthesis and Spark Plasma Sintering(2016-02-08) Lagos, M. A.; Agote, I.; Atxaga, G.; Adarraga, O.; Pambaguian, L.; EXTREMAT; PRINTEXThis work presents a novel processing method for the fabrication of particle reinforced Titanium Matrix Composites (TMCs). TMCs are a promising alternative to improve the mechanical properties of titanium alloys. In the processing method, the reinforcement (TiC-Ti) was obtained by Self-propagating High-temperature Synthesis (SHS). The composition of the reinforcement was Ti1.3C. An excess of titanium compared to the equiatomic TiC was introduced in the reaction in order to control the size of the reinforcement and to improve the compatibility between reinforcement and matrix. This reinforcement was mixed with Ti-6Al-4V powder and the final consolidation of the TMC was performed by Spark Plasma Sintering (SPS). The microstructure and mechanical characterisation of the TMCs are presented. Comparing tensile properties with conventional Ti-6Al-4V alloys, the materials developed in this work present higher young modulus and tensile strength. In addition, in order to study the possible scale up of SPS process for the production of TMCs, the manufacturing of large samples was studied.Item Fire retardancy of polypropylene composites reinforced with rice husks: From oxygen index measurements and cone calorimetry to large-scale single-burning-item tests: From oxygen index measurements and cone calorimetry to large-scale single-burning-item tests(2018-10-05) Schirp, Arne; Barrio, Aitor; BIOECONOMÍA Y CO2Rice husks containing 12 wt % inorganic silica were incorporated together with halogen‐free fire retardants in a polypropylene matrix and extruded into facade profiles. An increase in the amount of rice husks resulted in an increase in the oxygen index. The cone calorimetry measurements showed that all of the fire retardants tested significantly reduced the peak heat‐release rate (pHRR) and maximum average rate of heat emission (MARHE) of the formulations and moderately reduced total heat release. The best results in terms of MARHE were achieved for the formulation including 24% melamine‐coated ammonium polyphosphate. pHRR and MARHE were reduced with increasing amount of rice husks. Single‐burning‐item (SBI) tests were performed for the extruded profiles based on rice husks and, for comparison, wood flour. In the best case, a B‐s2, d0 classification was obtained. The results obtained from cone calorimetry and SBI tests were in agreement. Inc. J. Appl. Polym. Sci. 2018, 135, 46654.Item Obtaining preforms by additive fused deposition modelling (FDM) extrusion technology for the manufacture of high-performance composites(2022-06) Mendizabal, M. A.; Garcia, Maitane; Palenzuela, Luis; Hernández, Enrique; POLIMEROS; Tecnalia Research & Innovation; COMPOSITEThe composites industry is present in practically all industrial sectors with an annual growth rate of 5%. Its contribution to the priority "light-weighting" driver in the transport sector is key. The efficiency of the industry is made possible by the evolution of manufacturing processes that also improve the performance of the products obtained. For example, out-of-autoclave (OOA) processes can obtain high-performance composites such as those obtained by the autoclave process at lower costs. A key aspect in the development of this type of process is the preforming of continuous fibre reinforcements, which can achieve high fibre percentages while facilitating processing. Manufacturing these preforms currently requires multiple steps, equipment and tooling. TECNALIA's work developing the ADDICOMP technology, an alternative preform manufacturing method using an additive process based on Fused Deposition Modelling (FDM) is detailed in this article. This development is patented by Tecnalia and was conducted in 2 phases: (a) development of continuous fibre filaments coated with polymeric material and printable by FDM and (b) fine-tuning of FDM technology to print filaments with a very high content of continuous fibre.