Análisis de los diferentes tipos de desvulcanizado en la caracterización de nuevos materiales elastoméricos formados por la mezcla de estireno butadieno-caucho natural y mezclados con neumáticos fuera de uso (GTR)

This article proposes the creation of a new material useful for the industry from the mixture with rolls of two 50% virgin elastomers, styrene-butadiene (SBR) and natural rubber (NR) with tires out of use (GTR). These tires have been previously devulcanized following a number of techniques, which will be analyzed in this article, and then mixed with the virgin elastomer SBR/NR and the corresponding additives, revulcanized this new material in order to reach the mechanical properties, thermal and of structure that allow its use in the industry. Specifically, three types of samples have been analyzed; a first one formed by the virgin elastomer (SBR/NR), a second adding to the SBR/NR, GTR in the proportion of 20 phr (parts per hundred rubber), and a third adding to the SBR/NR, GTR in the proportion of 40 phr (more percentages were used in the mechanical tests in order to provide greater validity in the results). The GTR received has been devulcanized using different techniques: without devulcanitation (dn); mechanically devulcanized (dm); chemically and mechanically devulcanized (dcm); and microwave devulcanized (dmw). All these compounds have been tested with different tests; Mechanical, Crisscrossing Density, Gravimetric Thermal Analysis and Microscopy TestPeer ReviewedPostprint (published version

Analysis of the use of recycled aluminum to generate green hydrogen in an electric bicycle

This article proposes using recycled aluminum, generating hydrogen in situ at low pressure, to power a 250 W electric bicycle with a fuel cell (FC), to increase the average speed and autonomy compared to a conventional electric bicycle with a battery. To generate hydrogen, the aluminum–water reaction with a 6 M NaOH solution is used as a catalyst. This article details the parts of the generation system, the electronic configuration used, the aluminum- and reagent-loading procedure and the by-products obtained, as well as the results of the operation without pedaling, with a resistance equivalent to a flat terrain and at maximum power of the accelerator for one and two loads of about 100 g of aluminum each. This allows us to observe different hybrid strategies, with a low-capacity battery in each case. The goal is to demonstrate that it is possible to store energy in a long-lasting, transportable, low-pressure, and sustainable manner, using recycled-aluminum test tubes, and to apply this to mobilityObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantPostprint (published version

Study and characterization of the dielectric behavior of low linear density polyethylene composites mixed with ground tire rubber particles

The waste rubber vulcanizate, on account of its stable, cross-linked and three-dimensional structural arrangement, is difficult to biodegrade. Thus, the ever-increasing bulk of worn-out tires is a serious environmental issue and its safe disposal is still a challenging task reported widely by the scientific community. The rubber materials, once they end their useful life, may present difficulties to be reused or recycled. At present, only one tire recycling method is used, which involves grinding and separating steel and fibers from vulcanized rubber, and then using rubber for industrial applications, such as flooring, insulation, footwear. In this paper, a new compound material is presented from a base of reused tire powder (Ground Tire Rubber: GTR) as a mixer and linear low-density polyethylene (LLDPE) as a matrix. The reused tire powder, resulting from grinding industrial processes, is separated by sieving into just one category of particle size (<200 µm) and mixed with the LLDPE in different amounts (0%, 5%, 10%, 20%, 40%, 50% and 70% GTR). Due to the good electrical properties of the LLDPE, this study’s focus is settled on the electrical behavior of the obtained composites. The test of the dielectric behavior is carried out by means of DEA test (Dynamic Electric Analysis), undertaken at a range of temperatures varying from 30 to 120 °C, and with a range of frequencies from 1 to 102, to 3·106 Hz, from which permittivity, conductivity, dielectric constant and electric modulus have been obtained. From these experimental results and their analysis, it can be drawn that the additions of different quantities of GTR to LLDPE could be used as industrial applications, such as universal electrical cable joint, filler for electrical applications or cable tray systems and cable ladder system.Peer ReviewedPostprint (published version

Comparison of mechanical and electrical characteristics of various polymers blended with ground tire rubber (GTR) and applications

The massive manufacture of tires and the di culty of reducing the stocks of used tires is a serious environmental problem. There are several methods used for recycling wasted tires, one of which is mechanical crushing, in which vulcanized rubber is separated from steel and fibers, resulting in a ground tire rubber (GTR). This can be used in applications such as insulation for footwear work. The aim of the present investigation is to evaluate the use of the GTR when it is mixed with several types of polymer matrix by means of measuring its dielectric and mechanical properties of the resulting composites (polymer + GTR). The analysis is carried out using seven polymeric matrices mixed with di erent GTR concentrations. With the present study, it is intended to propose a way to reuse the tires out of use as an industrial work footwear insulation, by demonstrating the feasibility of the properties analyzedPeer ReviewedPostprint (published version

Ground Tire Rubber recycling in applications as insulators in polymeric compounds according to spanish UNE standards

In the present research, we investigated the conceivable outcomes of using ground tire rubber (GTR) particle polymeric blends. Special methods of restoring tires that are no longer in use include GTR retreading, GTR blending destined for recycling to attain raw substances utilized in other industrial application production processes, and the valorization of GTR for power/energy generation. The recycling of end-of-life tires enables the recovery of rubber, steel, and fibers, all of which are valid on the market as raw materials to be used for other processes. There are methods to recycle GTRs in a clean and environmentally friendly way. In the present research, several industrial applications of GTR polymer blends were developed and compared with standard values from the Spanish Association for Standardization (UNE) and the International Electrotechnical Commission (IEC). In order to analyze the viability in many of the industrial applications selected, certain compounds obtained from the GTR polymer blends were analyzed regarding their use in nine low requirement insulator applications. The research and analysis developed in this manuscript used standard values from the UNE and IEC, and these standard values were compared with the test values. The obtained results were used to provide an application list that could be helpful for industrial applications. In this research, the pre-owned polymers were as follows: polypropylene (PP), high-density polyethylene (HDPE), polystyrene (PS), acrylonitrile butadiene-styrene (ABS), ethylene vinyl acetate (EVA), polyvinyl chloride (PVC), and polyamide (PA). The filler used was GTR with particle sizes lower than 200 microns. The amounts of GTR particles in the compound materials were 0% (raw polymer), 5%, 10%, 20%, 40%, 50%, and 70% (the latter being found in polymeric blends). We discovered six plausible modern applications of GTR polymer blends as indicated by the UNE and IEC standards.Peer ReviewedPostprint (published version

Anàlisi comparativa de propietats termo estructurals i elèctriques entre el polietilè d'alta densitat (HD-PE) i l’HD-PE reforçat amb pneumàtics al final de la seva vida útil. Estudi d'aplicació com a dielèctric

El propósito del presente trabajo pasa por analizar la permitividad y el factor de pérdidas tanto del polietile-no de alta densidad (HD-PE), como del compuesto de matriz polimérica (HD-PE)reforzado con neumáticos fuera de uso (Ground Tire Rubber: GTR), con el fin de demostrar su viabilidad como material aislante eléc-trico (dieléctrico). Como es sabido, la incorporación de negro de humo en un polímero permite modificar su conductividad, y cómo el GTR lleva un porcentaje significativo de negro de humo, algunas de las pro-piedades eléctricas del nuevo compuesto cambiaran significativamente con respecto al polímero que es altamente aislante. El estudio se centrará, en un rango de frecuencias y temperaturas aptas para demostrar la viabilidad de este nuevo compuesto en usos indus-triales, enfocándolo principalmente en el análisis de la Permitividad, ya que es una propiedad clave para los condensadores. No obstante, también se caracterizará el comportamiento térmico y estructural, haciendo especial énfasis en el rango de trabajo del condensador (por debajo de los 100ºC). Finalmente, con el análisis estructural, se pretende contribuir al conocimiento de estos materiales compuestos provenientes de reciclaje, y así, aprovechar su potencial de reutilización, haciéndolos atractivos para las empresas interesadas en su relación rendimiento/precio.The purpose of this work is to analyze the permittivity and the loss factor of both high-density polyethylene (HD-PE), as well as the polymer matrix composite (HD-PE) reinforced with end-of-life tires (Ground Tire Rubber: GTR), in order to demonstrate its viability as electrical insulating material (dielectric). As is known, the incorporation of carbon black in a polymer allows its conductivity to be modified, and since the GTR carries a significant percentage of carbon black, some of the electrical properties of the new compound will change significantly with respect to the polymer that is highly insulating. The study will focus on a range of frequencies and temperatures suitable to demonstrate the viability of this new composite in industrial uses, focusing mainly on the analysis of Permitivity, since it is a key property for capacitors. However, the thermal and structural behavior will also be characterized, with special emphasis on the capacitor working range (below 100ºC). Finally, with the structural analysis, it is inten-ded to contribute to the knowledge of these composite materials from recycling, and thus, take advantage of their potential for reuse, making them attractive for companies interested in their performance/price ratio.El propòsit del present treball passa per analitzar la permitivitat i el factor de pèrdues tant del polietilè d'alta densitat (HD-PE), com del compost de matriu polimèrica (HD-PE) reforçat amb pneumàtics fora d'ús (Ground Tire Rubber: GTR ), amb la finalitat de demostrar la seva viabilitat com a material aïllant elèctric (dielèctric). Com és sabut, la incorporació de negre de fum en un polímer permet modificar la seva conductivitat, i com el GTR porta un percentatge sig-nificatiu de negre de fum, algunes de les propietats elèctriques del nou compost canvien significativament respecte del polímer, que és altament aïllant. L'estudi es centrarà, en un rang de freqüències i temperatures aptes per demostrar la viabilitat d'aquest nou compost en usos industrials, enfocant principalment en l'anàlisi de la Permitivitat, ja que és una propietat clau per als condensadors. No obstant això, també es caracteritzarà el comportament tèrmic i estructural, fent especial èmfasi en el rang de treball d’un condensador (per sota dels 100 º C). Finalment, amb l'anàlisi estructural, es pretén contribuir a el coneixement d'aquests materials compostos provinents de reciclatge, i així, aprofitar el seu potencial de reutilització, fent-los atractius per a les empreses interessades en la seva relació rendiment/preu.Peer ReviewedPostprint (published version

ISS quasi-steady accelerometric data as a tool for the detection of external disturbances during the period 2009-2016.

DOI: https://doi.org/10.1007/s12217-018-9612-yThe present work aims to investigate the degree of correlation existing between the information contained in the ISS reduced quasi-steady accelerometric data and different external mechanical disturbances (reboostings, dockings/undockings, berthings/deberthings and Extra Vehicular Activities), compiled for the period 2009 to 2016. The eight hour mean (Mean8h) and the eight hour root mean square (RMS8h) acceleration values, considered as reduced data, have been extracted from the quasi-steady records provided by NASA Principal Investigator Microgravity Services website. The advantage of applying the present strategy is to drastically reduce the amount of information to be processed all along these eight years. The Mean8h values have been used for the evaluation of trends as function of time while the RMS8h ones were used to define the level (weak, medium and strong) of the different kind of external mechanical disturbances considered. These criteria has been applied for approximately four hundred selected disturbances, compiled in the Annex. Results indicate that reboosting is always detected as a strong disturbance, while dockings/undockings, as weak ones, having lower, though detectable level, depending on the type of spacecraft considered. Extra Vehicular Activities are undetectable by the use of this reduced quasi- steady approach. The inverse problem, in other words, knowing the value of the RMS8h one could try to predict the kind of disturbance responsible of it, is thus feasible except for berthing/deberthings and Extra Vehicular Activities

Ground Tire Rubber Recycling in Applications as Insulators in Polymeric Compounds, According to Spanish UNE Standards

In the present research, we investigated the conceivable outcomes of using ground tire rubber (GTR) particle polymeric blends. Special methods of restoring tires that are no longer in use include GTR retreading, GTR blending destined for recycling to attain raw substances utilized in other industrial application production processes, and the valorization of GTR for power/energy generation. The recycling of end-of-life tires enables the recovery of rubber, steel, and fibers, all of which are valid on the market as raw materials to be used for other processes. There are methods to recycle GTRs in a clean and environmentally friendly way. In the present research, several industrial applications of GTR polymer blends were developed and compared with standard values from the Spanish Association for Standardization (UNE) and the International Electrotechnical Commission (IEC). In order to analyze the viability in many of the industrial applications selected, certain compounds obtained from the GTR polymer blends were analyzed regarding their use in nine low requirement insulator applications. The research and analysis developed in this manuscript used standard values from the UNE and IEC, and these standard values were compared with the test values. The obtained results were used to provide an application list that could be helpful for industrial applications. In this research, the pre-owned polymers were as follows: polypropylene (PP), high-density polyethylene (HDPE), polystyrene (PS), acrylonitrile butadiene-styrene (ABS), ethylene vinyl acetate (EVA), polyvinyl chloride (PVC), and polyamide (PA). The filler used was GTR with particle sizes lower than 200 microns. The amounts of GTR particles in the compound materials were 0% (raw polymer), 5%, 10%, 20%, 40%, 50%, and 70% (the latter being found in polymeric blends). We discovered six plausible modern applications of GTR polymer blends as indicated by the UNE and IEC standards

Caracterización del comportamiento eléctrico, mecánico y térmico de compuestos poliméricos y con mezclas provenientes del reciclaje

This doctoral thesis studies the physical properties of polymeric composite materials, with the addition of ground tire rubber particles (GTR) and the use of any of these compounds for the electrical industry, either as a semiconductor, roofing, piping, insulation and stuffed in the world of electric cables or electric industry in general to provide an outlet for reusable materials from tires and give a new application is interesting for industry and also provide a solution to the serious problem of recycling such waste are as difficult to reuse the tires out of use. The difficulty to eliminate stocks of abandoned tires or store is a serious environmental problem. At present, various methods for recycling used tires, such as mechanical grinding, which separates the vulcanized rubber and steel fibers, using the rubber in many applications such as flooring, insulation, shoes, etc.. The carbon black is an important component in the tires with rates up to 30%, which is used to improve the behavior of these abrasive. This thesis investigates the electrical behavior (conductivity, permittivity, electric module, ...) of different composite materials obtained by mixing different polymers with different percentages of GTR (up to 70%) see their response depending on the amount of GTR, also depending on the frequency and temperature and see the potential feasibility for use in specific applications in the electric field. For this thesis are done different mixtures of materials (polymer insulators) with GTR to study the microstructural properties, thermal, mechanical and dielectric, by performing several tests: test DEA (impedance), test Drive Strain, Young's modulus, elongation at break, tensile strength, hardness, microstructure analysis by electron microscopy and thermal analysis by DSC testing of all compounds that have been made and conclusions drawn as to affect the incorporation tire dust in different proportions of GTR(0-5-10-20-40-50 and 70% ) and with different particle sizes (500 µm). From then analyzes the information obtained from all the research done to extract conclusions, then analyzes the current regulations and how they might use some of the compounds analyzed by the electrical industry, and thus recovered difficult to recycle waste while helping to lower production costs by adding powder tires. In addition, this can mean that quantifies savings in the global market and the Spanish market while environmental factors are weighted, such as the CO2 emissions and the storage of this waste.A la present Tesi doctoral s'aborda l'estudi de propietats físiques de materials polimèrics compostos, amb l’addició de partícules neumàtic fora d’ús (NFU o GTR –en anglès-) triturat i l'aprofitament d'algun d'aquests compostos per a la indústria elèctrica, ja sigui com a semiconductor, cobertes, canalitzacions, aïllament i farcits, en el món dels cables elèctrics o la indústria elèctrica en general per donar sortida a materials reutilitzables provinents de pneumàtics fora d'ús i donar una nova aplicació que sigui interessant per a la indústria i alhora donar una solució al greu problema del reciclatge d'aquest tipus de residus de difícil reutilització com son els neumàtics fora d’ús. La dificultat per eliminar els estocs de pneumàtics abandonats o emmagatzemar constitueix un greu problema mediambiental. En l'actualitat, s'utilitzen diversos mètodes per al reciclatge de pneumàtics, com la trituració mecànica, en la qual se separa el cautxú vulcanitzat de l'acer i les fibres, utilitzant aquest cautxú en nombroses aplicacions com paviments, aïllants, calçat, etc. El negre de fum és un component important en els pneumàtics amb percentatges de fins al 30%, que s'utilitza per millorar el comportament abrasiu d'aquests. En aquesta tesi doctoral s'investiga el comportament elèctric (conductivitat, permitivitat, mòdul elèctric, ...) de diferents materials compostos obtinguts mitjançant la barreja de diferents polímers amb diferents percentatges de NFU (fins a un 70%), veure la seva resposta en funció de la quantitat de NFU, en funció també de la freqüència i de la temperatura i veure la possible viabilitat per a ser utilitzats en aplicacions concretes en l'àmbit elèctric. Per a la present tesi doctoral es realitzen diferents mescles de materials (polímers aïllants), amb NFU per estudiar les propietats microestructurals, tèrmiques, mecàniques i dielèctriques, mitjançant la realització de diversos assaigs: assaig DEA (espectroscòpia d'impedàncies), assaig Tracció-Deformació , Mòdul de Young, Allargament a la ruptura, Resistència a la Ruptura, Duresa, Anàlisi de Microestructura mitjançant Microscòpia Electrònica i anàlisi tèrmica mitjançant assaig DSC de tots els compostos que s'han realitzat, i s'extreuen conclusions de com afecta la incorporació de pols de pneumàtic en diferents proporcions (0-5- 10-20-40-50 i 70% de NFU) i amb mides de partícula diferents (500 μm). A partir d'aquí s'analitza la informació obtinguda de tota la investigació realitzada per extreure conclusions, tot seguit s'analitza la normativa vigent actual i de quina manera es podria utilitzar algun dels compostos analitzats per a la indústria elèctrica, i així es valoritza un residu de difícil reciclatge al mateix temps que es contribueix a baixar costos de producció per addició de pols de Pneumàtic Fora d'Ús. A més es quantifica en que pot suposar aquest estalvi a nivell mundial i espanyol a la vegada que es ponderen factors mediambientals, com pot ser l'emissió de CO2 i l'emmagatzematge d'aquest residu

Análisis de los diferentes tipos de desvulcanizado en la caracterización de nuevos materiales elastoméricos formados por la mezcla de estireno butadieno-caucho natural y mezclados con neumáticos fuera de uso (GTR)

This article proposes the creation of a new material useful for the industry from the mixture with rolls of two 50% virgin elastomers, styrene-butadiene (SBR) and natural rubber (NR) with tires out of use (GTR). These tires have been previously devulcanized following a number of techniques, which will be analyzed in this article, and then mixed with the virgin elastomer SBR/NR and the corresponding additives, revulcanized this new material in order to reach the mechanical properties, thermal and of structure that allow its use in the industry. Specifically, three types of samples have been analyzed; a first one formed by the virgin elastomer (SBR/NR), a second adding to the SBR/NR, GTR in the proportion of 20 phr (parts per hundred rubber), and a third adding to the SBR/NR, GTR in the proportion of 40 phr (more percentages were used in the mechanical tests in order to provide greater validity in the results). The GTR received has been devulcanized using different techniques: without devulcanitation (dn); mechanically devulcanized (dm); chemically and mechanically devulcanized (dcm); and microwave devulcanized (dmw). All these compounds have been tested with different tests; Mechanical, Crisscrossing Density, Gravimetric Thermal Analysis and Microscopy TestPeer Reviewe