This research aimed to evaluate the influence of styrene–butadiene–styrene (SBS) compatibilizer in the polystyrene blends properties with a recycled styrene–butadiene rubber compound. The SBS conte...

Incorporation of a recycled rubber compound from the shoe industry in polystyrene: Effect of SBS compatibilizer content:

The electrodeposition of indium on copper substrates is studied in an acid sulfate solution for applications in CuInS 2 (CIS) and Cu(InGa)Se 2 (CIGS) solar cells. The study is focused on the film morphology and thickness uniformity on the nanometer scale. A two-step film growth behavior was observed, a conformal smooth film growth followed by a three-dimensional island growth. A hypothesis involving the Cu-In alloy formation and the Cu-In interdiffusion is proposed. While the room temperature alloy formation promotes the conformal deposition of a few monolayers of alloy, the fast interdiffusion between Cu and In further extends this alloy formation to a thicker layer and delays the typical island formation-growth phenomenon.

Electrodeposition of Indium on Copper for CIS/CIGS Solar Cell Applications

Environmentally friendly polymer blends between post-consumer PET-G and bio-based poly(ethylene 2,5 furanoate) (PEF) have been prepared. The PET-G granules were obtained from the post-consumer glycol-modified poly(ethylene terephthalate) PET-G foils from Nicrometal S.A. as a result of materials recycling. PEF was synthesized from dimethyl furan-2,5-dicarboxylate and 1,2-ethylene glycol (BioUltra) by a two-stage melt polycondensation process. According to the calculations followed by Hoy's method, one has studied the miscibility of the components in the blend. The molecular structure of PET-G/PEF blends was analyzed by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, while the morphology of the blends was determined by Scanning Electron Microscopy (SEM). To evaluate phase transition temperatures, as well as the thermal effects in PET-G/PEF blends, Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA), and Thermogravimetric Analysis (TGA), were performed. Tensile tests revealed that along with an increase in the amount of PEF, an increase in Young's modulus was observed. Besides, the existence of interfacial interactions between polymers, especially in the case of PET-G/PEF 80/20, enabling the PET-G chains to form a network structure with the PEF by reacting with their functional groups, allows observation of a synergistic effect in the improvement of thermal stability and water absorption.

https://www.mdpi.com/1996-1944/13/12/2673/pdf

Environmentally Friendly Polymer Blends Based on Post-Consumer Glycol-Modified Poly(Ethylene Terephthalate) (PET-G) Foils and Poly(Ethylene 2,5-Furanoate) (PEF): Preparation and Characterization.

The vulcanized rubber waste from the shoe industry causes environmental damage when it is incinerated or inappropriately discarded, turning this into a problem of major concern. Therefore, this study had as the main objective the Polystyrene (PS) toughening using different contents of white vulcanized styrene-butadiene rubber (SBRr) waste produced in the shoe industry. The mixtures were initially prepared in a co-rotational double screw extruder and, thereafter, the extruded granules were injection molded. Analyzed were the rheological, mechanical, thermomechanical properties and morphology of the produced blends. The rheological results showed a viscosity increase as the SBRr concentration was augmented, leading to a higher stability when compared to pure Polystyrene. Verified was an increase of impact resistance of 189% to the blend that contained 50% of SBR rather than pure Polystyrene. On the other hand, the traction properties, hardness Shore D, thermal deflection temperature (HDT) and Vicat softening temperature of the blends tended to decrease when compared to pure Polystyrene results. However, as this SBR waste is made up of a complex mixture of SBR, filler, processing additions, curing agents and stabilizers, it probably acted in the sense of not causing such a drastic reduction of the properties, even using a high concentration of SBRr waste. The morphologies obtained with the SEM method (Scanning Electronic Microscope) were quite different and typical of immiscible blends. The results show that it is possible to obtain a new material with good properties, valuing a discarded industrial waste and avoiding environment aggression.

/pdf/toughening-of-polystyrene-using-styrene-butadiene-rubber-58x2i6py20.pdf

Toughening of polystyrene using styrene-butadiene rubber (SBRr) waste from the shoe industry

Electrowinning represents a promising methodology for recovery of strategical, scarce metals. In this study, an indium electrowinning process using a sulfate electrolyte on stainless steel, nickel, titanium, aluminum and copper (SS, Ni, Ti, Al and Cu) cathodes was investigated. Firstly, cyclic voltammetry carried out at 15 mV/s scanning rate and 25 °C temperature evaluated the suitability of electrolyte and the surface reactivity on different metal cathodes. Subsequently, indium was deposited using a current density of 25 A/m2 for 22 h at 40 °C and pH 2.3. After electrowinning process, analysis of specific energy consumption (SEC), current efficiency (CE) morphological (SEM/EDX), and crystallographic (XRD) tests on obtained deposits were performed. Cyclic voltammetry results revealed that the chemical reagents of solution stabilize the indium reduction reaction, while Ni cathode showed the highest current intensity for reduction reaction followed by SS, Ti, Cu, and Al. With a significant CE and SEC performance, Ni and SS cathodes reached around 93 % CE and 1.67 kW h/kg SEC, respectively. Referring to Ti cathode, other optimization tests should be performed to enhance obtained results. After deposition process, different surface morphologies and different crystallinity degree can be observed for each deposit, being common the presence of surface defects. The findings of this investigation allowed to determine the most suitable cathode for indium electrowinning from sulfate electrolyte.

Indium electrowinning study from sulfate aqueous solution using different metal cathodes

Neodymium recovery from scrap magnet using ammonium persulfate

This study evaluates the influence of recycled rubber (RR) with a specific particle size in the properties of blends, blended recycled polypropylene/polyethylene (RPP) and RR (RPP/RR). The proportions of RPP/RR employed to obtain the blends were as follows: 90/10 (PP90), 75/25 (PP75), 60/40 (PP60) and 45/55 (PP45). The particle size of the RR employed was 850 µm . The properties of the blends were evaluated by rheometric, thermogravimetric (TGA), differential scanning calorimetric (DSC), scanning electronic microscopy (SEM), density, melt flow index and tensile analysis. The maximum torque increased with the RPP content. By DSC analysis, it was observed that the RPP exhibited two melting temperatures, the first corresponded to low density polyethylene (LDPE) and the second to polypropylene (PP). Furthermore, the RR affected the crystallinity of the RPP. By using SEM and TGA analyses, it was determined that the RPP as well as RR contained fillers. The blend densities were higher than those of RPP. The melt flow index exhibited a trend with the amount of RR.PACS: 61.25.hk, 83.80.Va, 81.05.Lg

/pdf/effect-of-the-recycled-rubber-on-the-properties-of-recycled-2l2fzgiw9u.pdf

Effect of the Recycled Rubber on the Properties of Recycled Rubber/Recycled Polypropylene Blends

Indium electrowinning kinetics on titanium, aluminum and copper supports from sulfate solution

Resumen Un cemento oseo se sintetizo a partir CaCO3 y CaHPO4, en un tratamiento termico a 1.400 °C, el material sintetizado fue enfriado rapidamente, con un chorro de aire. El cemento oseo fue mezclado con biovidrio en un 10% en peso (BC-10BG) y luego molido y caracterizado mediante Distribucion de Tamano de Particula (DTP), Difraccion y Fluorescencia de rayos X (DRX y FRX). La mezcla, cemento-biovidrio, y el cemento solo fueron caracterizados fisicomecanicamente con pruebas de resistencia a la compresion, microdureza, tiempo de cohesion y fraguado. Con el fin de observar tendencias a la precipitacion en los estudios in-vitro, se evaluaron adicionalmente otras dos composiciones con biovidrio del 5 y del 15% en peso, por DRX, SEM y FTIR-ATR. Las fases cristalinas encontradas inicialmente corresponden en el cemento oseo al α-TCP, β-TCP, Ca2P2O7 y CaHPO4, por su parte en el biovidrio se detecto, en una parte de su estructura cristalina, la fase whitlockita. En terminos fisicos, los tiempos de manipulacion y las propiedades mecanicas corresponden a un cemento para el relleno de cavidades oseas. Las pruebas in-vitro mostraron un efecto bioactivo progresivo conforme aumenta el tiempo de exposicion.

Erwin Ciro

Papers

Neodymium recovery from scrap magnet using ammonium persulfate

Indium electrowinning study from sulfate aqueous solution using different metal cathodes

Effect of the Recycled Rubber on the Properties of Recycled Rubber/Recycled Polypropylene Blends

Indium electrowinning kinetics on titanium, aluminum and copper supports from sulfate solution

Elaboración de un cemento óseo de fosfato de calcio con una adición de biovidrio