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The present work aimed to prepare novel bio-based composites by adding fillers coming from agro-wastes to an acrylate epoxidized soybean oil (AESO) resin, using liquid crystal display (LCD) 3D printing. Different photocurable formulations were prepared by varying the reactive diluents, iso-bornyl methacrylate (IBOMA) and tetrahydrofurfuryl acrylate (THFA). Then, two fillers derived from different industrial wastes, corn (GTF) and wine (WPL-CF) by-products, were added to the AESO-based formulations to develop polymer composites with improved properties. The printability by LCD of the photocurable formulations was widely studied. Bio-based objects with different geometries were realized, showing printing accuracy, layer adhesion, and accurate details. The thermo-mechanical and mechanical properties of the 3D-printed composites were tested by TGA, DMA, and tensile tests. The results revealed that the agro-wastes' addition led to a remarkable increase in the elastic modulus, tensile strength, and glass transition temperature in the glassy state for the systems containing IBOMA and for flexible structures in the rubbery region for systems containing THFA. AESO-based polymers demonstrated tunable properties, varying from rigid to flexible, in the presence of different diluents and biofillers. This finding paves the way for the use of this kind of composite in applications, such as biomedical for the realization of prostheses. [ABSTRACT FROM AUTHOR]

Rapid solidification techniques, such as gas atomisation, have been widely implemented in metallic alloys/composites to increase solid solubility, avoid or mitigate segregation phenomena, and favour metastable phase formation to enhance performance. Particularly, gas atomisation can enhance the solid solubility of low diffusion coefficient elements like Fe, Ni, Mn, Zr, and Cr in the α-Al matrix, yielding metastable phases. As a result, Al alloys exhibit excellent strength at high temperatures. In this study, the AISI 304L alloy was employed to introduce Fe, Ni, and Cr elements into the AlSi10Mg alloy through gas atomisation, resulting in the formation of two distinct hypereutectic AlFe-based alloys: AlFe9Si8Cr2Ni and AlFe18Si8Cr5Ni2. Gas-atomised alloy powders were separated into different size fractions by sieving and characterised using X-ray diffraction, differential scanning calorimetry, optical microscopy, and scanning electron microscopy. Microstructural analyses revealed dendritic patterns with distinct phases, highlighting the influence of the alloying element content on the solidification processes. Furthermore, a synergic evaluation of the XRD and EDS analysis results allowed the identification of intermetallic phases and their distribution in the two systems. [ABSTRACT FROM AUTHOR]

Metallic powders are widely utilized as feedstock materials in metal additive manufacturing (MAM). However, only a limited number of alloys can currently be processed using these technologies, with most of them being casting alloys. The objective of this study is to investigate novel aluminum alloys produced via a close-coupled gas atomizer (CCGA) by adding an increasing amount of copper (4, 8, and 20 wt%) to an AlSi10Mg alloy. The obtained powders were fully characterized to evaluate the effect of copper, a well-established strengthener for aluminum alloys, in order to correlate the obtained hardness to the powder phase composition and microstructure. In particular, a dendritic microstructure was observed in all alloys, and, as the copper content was increased, the size of the secondary dendrite arm spacing (SDAS) decreased progressively. Consequently, the hardness measured on the powder cross-section linearly increased with the copper content, and the hardness value of 185 ± 13 HV of the AlCu20Si10Mg composition was found to be twice that of the AlSi10Mg alloy (88 ± 5 HV). [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) has opened new frontiers in precision medicine, giving the possibility of fabricating patient‐customized scaffolds to replace damaged tissues. In particular, bone tissue engineering (BTE) has benefited the most from the introduction of AM. In contrast, the impelling environmental issues are moving all the industrial sectors toward a sustainable development, avoiding the use of nonrenewable resources. Since thermoplastic polymers, such as poly(lactic acid) (PLA) and polycaprolactone (PCL), are massively used in the biomedical field, the primary objective of this study is to encourage the use of biodegradable and compostable materials also in BTE. Focusing on poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBH), an eco‐friendly material with good biocompatibility and biodegradability, reinforced with cellulose nanocrystals (CNCs), 3D‐printed scaffolds through fused filament fabrication (FFF) are realized. Since vascularization is mandatory for bone regeneration processes and for a successful scaffold integration, the angiogenic potential of different PHBH–CNC formulations in vitro is tested, evaluating the colonization of the scaffolds by endothelial cells, and in ovo with the chorioallantoic membrane (CAM) assay. The final goal is to define the best geometry of the scaffold and PHBH–CNC composition that can trigger vascularization in BTE applications, with the ultimate aim of giving greater guarantees of osseointegration. [ABSTRACT FROM AUTHOR]

Titania nanoparticles suspended in benzyl alcohol (BzOH) were generated by nonhydrolytic sol-gel process starting from titanium tetrachloride. The obtained suspensions were mixed with 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate epoxy resin, and the formulations were cured in the presence of ytterbium(III) trifluorome-thanesulfonate as cationic initiator. The thermally activated cationic ring-opening polymerization produced a three-dimensional network in which the suspending medium BzOH was covalently linked to the epoxy network according to the 'activated monomer' mechanism during the propagation step. The presence of titania nanoparticles resulted in a reinforcing and stiffening effect due to both their hydrodynamic effect and, most important, a significantly higher cross-linking density of the composite material with respect to the unfilled epoxy resin. A comparison with similar composites obtained by physical incorporation of preformed titania particles was also reported in order to compare the in situ and ex situ filler generation for preparing nanocomposites., INTRODUCTION The field of organic-inorganic hybrid materials has become of great interest thanks to the possibility to combine some peculiar mechanical and functional properties of both organic polymers and inorganic [...]