To increase the applications of FDM (fusion deposition modeling) 3D printing in electronics, it is necessary to develop new filaments with good electrical properties and suitable processability. In this work, polymer composites filament-shaped with superior electrical performance based on polylactic acid (PLA) carbon nanotubes and lignin blends have been studied by combining solution mixing and melt blending. The results showed that composites achieve electrical percolation from 5 wt.
View Article and Find Full Text PDFWith increasing environmental awareness, lignin will play a key role in the transition from the traditional materials industry towards sustainability and Industry 4.0, boosting the development of functional eco-friendly composites for future electronic devices. In this work, a detailed study of the effect of unmodified lignin on 3D printed light-curable acrylic composites was performed up to 4 wt.
View Article and Find Full Text PDFThere is need for developing novel conductive polymers for Digital Light Processing (DLP) 3D printing. In this work, photorheology, in combination with Jacobs working curves, efficaciously predict the printability of polyaniline (PANI)/acrylate formulations with different contents of PANI and photoinitiator. The adjustment of the layer thickness according to cure depth values () allows printing of most formulations, except those with the highest gel point times determined by photorheology.
View Article and Find Full Text PDFA study of the radon activity concentration was carried out at the School of Computer Science of 'Universidade da Coruña' (UDC, Spain). For this purpose, building location, the type of soil and the construction materials were analysed. Subsequently, the radon activity concentration was determined using two different techniques: measurement in situ with an on-site ionization chamber detector (short term) and measurement with trace detectors (long term).
View Article and Find Full Text PDFIn the last decade, Fused Deposition Modeling (FDM) has gained popularity for allowing the fabrication of pieces with complex shapes. The final quality of the pieces is strongly linked to the shape, size and surface finish of the strands deposited successively, which themselves depend on the printing parameters and extruded material properties. In this work, we present an experimental characterization of an extruded and deposited single strand of Poly-Lactic Acid (PLA), by means of high-speed visualization of the bead region between the substrate and the nozzle, where the molten polymer is still in liquid phase.
View Article and Find Full Text PDFJ Agric Food Chem
December 2013
In this work, natural plasticizers-modified polypropylenes intended for food active packaging were developed. Sunflower oil, olive oil, and soy lecithin, without any known harmful effects or toxicity, were employed as natural plasticizers, also implementing the attractiveness of using synthetic plastics on active packaging developments. Their incorporation during the extrusion of polypropylene was tried as a means to obtain polymers with improved diffusion paths, allowing differences in antioxidant release rates for active packaging materials.
View Article and Find Full Text PDFThe feasibility of novel controlled release systems for the delivery of active substances from films intended for food packaging was investigated. Because polyolefins are used highly for food-packaging applications, the reported high retention degree of antioxidants has limited their use for active packaging. Thus, in this study, PP films modified with different chain extenders have been developed to favor and control the release rates of the low molecular weight antioxidant tocopherol.
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