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In recent decades, polycotton canvases, which are made with mixtures of cotton and synthetic fibres, have appeared on the market and are used by artists. The aim of this article is to identify, characterise, and evaluate the mechanical behaviour before and after an ageing process of three representative types of polycotton canvases, and to compare them with the more traditional and studied linen canvases. The characterisation results provide information on the proportion of fibres in the three polycottons studied, as well as new technologies in the spinning and sizing of their yarns. A new measurement system that improves the accuracy of measuring the effective cross-sectional area of the canvas has been developed. The dynamometric and bursting tests results allow us to quantify the lower resistance of polycotton canvases compared to traditional linen. Additionally, they reveal some peculiarities such as a greater stiffness of the warp compared to the weft threads in polycotton canvases. This is opposite to what occurs in linen canvases. The differences between warp and weft threads in polycotton canvases, along with the use of the open-end spinning system, provide valuable information for proper conservation and future restoration interventions. Additionally, the open-end spinning system involves a greater water absorption capacity compared to ring yarn fabrics, The authors express their gratitude to Núria Oriols and Carme Ramells from the Museu Nacional de Catalunya, MNAC, for their contribution in the interpretation of the FTIR results. We also thank Núria Pedragosa and Daniel Morales for their her help in providing information on some paintings (MNAC, Museu Nacional de Catalunya, and MACVAC, Museo de Arte Contemporáneo de Castellón). The authors also greatly appreciate the support of Beatriz Amante, Edwin Pinto, Bartomeu Salas, Montse Guerrero, and Paloma López from the Intexter Institute of Textile Research and Industrial Cooperation of Terrassa, for their invaluable support in the experimental part of the study and for guiding in the use of their instruments, equipment and laboratories, Postprint (published version)

En este artículo se presenta el proyecto RECYWASTEX, propuesta que pretende avanzar en el conocimiento del reciclado mecánico de textiles que se acumulan en los vertederos. También se describe el equipamiento de que dispone el Grupo de Investigación en Tecnología Textil-TECTEX, del Instituto de Investigación Textil y Cooperación industrial (INTEXTER) del Campus de Terrassa de la Universitat Politècnica de Catalunya relativo al reciclaje textil mecánico de fibra a fibra, Postprint (published version)

This research aimed to examine how household washing influences the colorimetric characteristics of natural colored organic cotton (NaCOC) fabrics. The colorimetric properties of (NaCOC) fabrics were assessed both before and after undergoing washing for up to 30 cycles. The findings indicated that washing significantly influenced the colorimetric properties of naturally dyed cotton fabrics, as evidenced by changes in lightness and saturation. The most significant difference in color between the two samples was observed after the initial wash, highlighting the reduction in both parameters, lightness and saturation, after this first washing. Between the second and fifth washes, there are notable differences in these parameters. However, from the fifth wash, the variation in color difference was minimal. Additionally, the FTIR-ATR analysis of the extracts in petroleum ether and subsequently in ethanol of the NaCOC fabrics, before and after home washing, in conjunction with a comparison with shrinkage, demonstrated that the latter process was accountable for the darkening of the sample, The authors would like to express their gratitude to Mr. Francisco José Barahona, Mr. Oliver García, Mrs. Montserrat Guerrero, Mr. Ferran Parés and Mrs. Zurine Ramírez for their assistance in the experimental work, Postprint (published version)

The inclusion of particles in a polymeric substrate to achieve certain properties is a well-known practice. In the case of textile substrates, this practice may deeply affect the structure of the produced yarns, as even a filament with no textile applications can be obtained. In this manuscript, titanium dioxide (TiO2) particles were incorporated into polyester (PET) chips and the influence of these fillers on the properties of yarn and fabric, and the ultraviolet protection factor (UPF) was assessed. For this purpose, rutile and anatase crystalline forms of TiO2, as well as the size of the particles, were evaluated. Moreover, parameters such as mechanical properties, orientation of the macromolecules and thermal behavior were analyzed to ensure that the textile grade is maintained throughout the production process. The results showed that the inclusion of micro- and nanoparticles of TiO2 decreases the molecular weight and tenacity of PET. Also, although orientation and crystallinity varied during the textile process, the resulting heatset fabrics did not present important differences in those parameters. Finally, the attainment of textile-grade PET-TiO2 fabrics with UPF indexes of 50+ with both rutile and anatase and micro- and nano-sized TiO2 forms was demonstrated, The authors gratefully acknowledge the financial support for this research from the Ministry of Science and Innovation of Spain (project MAT2010-20324-CO2-01) and from the National Secretary of Higher Education Science Technology and Innovation of Ecuador (SENESCYT) for fellowship No. CZ02-000926-2018, Postprint (published version)

El grupo de investigación de ingeniería textil (TECTEX) INTEXTER y del Departamento de Ciencia e Ingeniería de Materiales de la Universitat Politècnica de Catalunya tiene como principal objetivo el desarrollo y optimización de nuevos materiales, procesos y tecnologías de la cadena de valor de la industria textil (desde la producción y caracterización de fibras y tejidos, procesos de tintura y acabado, hasta productos textiles). La finalidad de la actividad de nuestro grupo de investigación es reducir los impactos ambientales, aumentar la circularidad y optimizar los materiales, procesos y tecnologías textiles, así como desarrollar soluciones de alto valor añadido. Todo ello para contribuir a la creación de un sector textil más sostenible y competitivo. En particular, la investigación que llevamos a cabo en TECTEX se centra en contribuir a resolver los retos globales y las necesidades de competitividad industrial europea relacionadas con la transición ecológica y la transición digital, así como con el desarrollo de nuevas soluciones de alto valor añadido enfocadas principalmente al desarrollo de dispositivos y sistemas para aplicaciones biomédicas. En este artículo se presentarán los principales proyectos que actualmente estamos liderando desde nuestro grupo de investigación, como son los proyectos relacionados con la obtención de fibras naturales a partir de residuos agrícolas (HEMPQUAL), la obtención de colorantes naturales a partir de residuos agrícolas (OLIWASTEX), el reciclaje de residuos textiles por métodos mecánicos (RECYWASTEX), el desarrollo de materiales compuestos de cemento reforzados con fibras y estructuras textiles (RECYBUILDMAT), el electrohilado para aplicaciones biomédicas (ONCOFIBRAS y la aplicación del blockchain y trazabilidad a la industria textil (TRICK), Los proyectos presentados en este artículo han recibido financiación de las siguientes entidades: Gobierno de España, Agencia estatal de investigación: PID2019-108067RB-I00/ AEI/10.13039/501100011033 (proyecto RECYBUILDMAT) Gobierno de España y Unión Europea: TED2021-130611B-I00 (proyecto RECYWASTEX), financiado por MCIN/AEI/10.13039/501100011033 y por la Unión Europea “NextGenerationEU”/PRTR Generalitat de Catalunya: ACE034/21/000053 (proyecto ONCOFIBRAS); 2021PROD00074 (proyecto OLIWASTEX), 2021PROD00079 (proyecto HEMPQUAL) Unión Europea: H2020-958352-TRICK (proyecto TRICK), Postprint (published version)

The accelerated aging of polyethylene terephthalate (PET) multifilament yarns containing nano or microparticles of titanium dioxide (TiO2), silicon carbide (SiC), or fluorite (CaF2) at a maximum percentage of 2% has been studied. For this, the yarn samples were introduced into a climatic chamber at 50 °C, 50% relative humidity, and an ultraviolet A (UVA) irradiance of 1.4 W/m2. They were then removed from the chamber after periods of between 21 and 170 days of exposure. Subsequently, the variation in weight average molecular weight, number molecular weight, and polydispersity was evaluated by gel permeation chromatography (GPC), the surface appearance was evaluated using scanning electron microscopy (SEM), the thermal properties were evaluated using differential scanning calorimetry (DSC), and the mechanical properties were evaluated using dynamometry. The results showed that, at the test conditions, there was degradation in all of the exposed substrates, possibly due to the excision of the chains that make up the polymeric matrix, which resulted in the variation in the mechanical and thermal properties depending on the type and size of the particle used. This study provides insight into the evolution of the properties of PET-based nano- and microcomposites and might be helpful when selecting materials for specific applications, which is of great interest from an industrial point of view, The authors gratefully acknowledge the financial support for this research from the Ministry of Science and Innovation of Spain (Project MAT2010-20324-CO2-01) and the National Secretary of the Higher Education Science Technology and Innovation of Ecuador (SENESCYT) for Fellowship No. CZ02-000926-2018, Postprint (published version)

En aquest projecte s’ha estudiat un tractament de deslignificació a una planta pilot de tres tipus de sacs de jute diferents, obtinguts a partir de la importació del cafè al port de Barcelona, per a l’obtenció de fils a partir de mescles amb liocel. Per al procés químic, s’ha fet un estudi per la utilització d’un agent segrestant que ha permès fer els tractaments dels sacs de jute amb hidròxid sòdic, amb peròxid d’hidrogen i la neutralització final amb aigua de xarxa urbana. S’ha utilitzat una planta pilot per a deslignificar els sacs de jute i, mitjançant espectrofotometria FTIR-ATR s’ha demostrat la disminució de la quantitat de lignina i hemicel·lulosa. La matèria tractada ha estat desfibrada i s’han preparat quatre fils diferents, 100% liocel (CLY) i tres fils de barreja liocel/jute (CLY/JU) amb una composició igual (75% CLY 25% JU ), on la variable és el tipus de jute utilitzat (Vietnam, Ruanda i Hondures). Els fils han estat caracteritzats mitjançant dinamometria donant resultats que, encara que inferiors a les de liocel 100% tenen valors òptims per a la seva utilització. S’ha determinat la composició final dels fils ja que, durant el procés, hi ha hagut pèrdues considerables. La composició final dels fils determinada tant per les pèrdues mecàniques, com químicament és de 82/18 CLY/JU i 83/17 CLY/JU, respectivament. Finalment, l’anàlisi del tacte dels teixits obtinguts amb aquests fils ha resultat que la mostra amb jute de Ruanda té la pitjor suavitat de totes les mostres, seguida per la mostra amb jute d’Hondures i, tenint un tacte similar però lleugerament inferior a les mostres de 100% CLY, es troba el teixit realitzat amb el jute de Vietnam

The dyeing and finishing step represents a clear hotspot in the textile supply chain as the wet processing stages require significant amounts of water, energy, and chemicals. In order to tackle environmental issues, natural dyes are gaining attention from researchers as more sustainable alternatives to synthetic ones. This review discusses the topic of natural dyes, providing a description of their main features and differences compared to synthetic dyes, and encompasses a summary of recent research in the field of natural dyes with specific reference to the following areas of sustainable innovation: extraction techniques, the preparation of substrates, the mordanting process, and the dyeing process. The literature review showed that promising new technologies and techniques have been successfully employed to improve the performance and sustainability of natural dyeing processes, but several limitations such as the poor fastness properties of natural dyes, their low affinity with textiles substrates, difficulties in the reproducibility of shades, as well as other factors such as cost-effectiveness considerations, still prevent industry from adopting natural dyes on a larger scale and will require further research in order to expand their use beyond niche applications, This work was funded by AGAUR within the OliWasTex project (2021-PROD00074), Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura, Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura::9.4 - Per a 2030, modernitzar les infraestructures i reconvertir les indústries perquè siguin sostenibles, usant els recursos amb més eficàcia i promovent l’adopció de tecnologies i processos industrials nets i racionals ambiental­ment, i aconseguint que tots els països adoptin mesures d’acord amb les capacitats respectives, Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables, Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.5 - Per a 2030, disminuir de manera substancial la generació de residus mitjançant polítiques de prevenció, reducció, reciclatge i reutilització, Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.2 - Per a 2030, assolir la gestió sostenible i l’ús eficient dels recursos naturals, Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.4 - Per a 2020, aconseguir la gestió ecològicament racional dels productes químics i de tots els residus al llarg del seu cicle de vida, de conformitat amb els marcs internacionals convinguts, i reduir-ne de manera significativa l’alliberament a l’atmosfera, a l’aigua i al sòl a fi de minimitzar-ne els efectes adversos sobre la salut humana i el medi ambient, Postprint (published version)

El presente trabajo de investigación se centra en la obtención y caracterización de mezclas de fibras celulósicas y yute con el propósito de explorar su aplicabilidad en la industria textil. Inicialmente, se deslignificó el yute proveniente de sacos de café para eliminar la lignina, lo que resultó en fibras de yute postconsumo. Estas fibras se mezclaron con algodón y liocel en diferentes proporciones para producir hilos de distintos títulos y tejidos de diferentes longitudes de malla. Se llevó a cabo una encuesta para evaluar las propiedades táctiles y visuales de los hilos y tejidos obtenidos. Se elaboró una propuesta de aplicación en varios sectores industriales y se desarrolló un estudio de viabilidad económica. Además, se diseñó y creó una materioteca para visualizar y evaluar las propiedades de los materiales textiles obtenidos, lo que facilita el análisis y las futuras aplicaciones de los sustratos textiles. Los resultados indican que las mezclas de 80-70% de fibras celulósicas y 20-30% de yute, junto con un tratamiento superficial, son especialmente prometedoras para su uso en la industria de la moda y la decoración del hogar. Este proyecto contribuye al avance de la industria textil al ofrecer una alternativa sostenible y versátil en forma de mezclas de fibras celulósicas y yute, demostrando su potencial en distintos campos y destacando su importancia en la búsqueda de soluciones textiles respetuosas con el medio ambiente

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Raw hemp (Cannabis sativa L.) was subjected to alkaline delignification with the application of NaOH ranging from [0.125M] to [1M] for times from 5 to 480¿min. Lignin contents of the original and delignified samples were determined. The samples were subjected to thermogravimetric analysis (TGA) under a N2 atmosphere with temperatures ramped from 25 to 600¿°C at 10¿°C min-1. Lignosulfonates samples of low, medium and high molecular weight were subjected to the same TGA and showed that lignin decomposed over the entire temperature range. The contributions of lignin to the mass loss during thermal decomposition of hemp and kinetics of lignin content and the most relevant TGA results were determined. Regression models estimating the lignin content of the fibers based on TGA results were formulated. These models allow for the prediction of mean lignin content within ± 0.1% (based on dry weight of pulp) in the central range of the experimental field, info:eu-repo/grantAgreement/MINECO/1PE/MAT2016-79352-R, Postprint (author's final draft)

The objective of this work was to assess the possibility of dyeing a substrate composed of non-textile industrial hemp using natural dyes from common madder (Rubia Tinctorum L.) and calendula (Calendula Officialis) and tannin and alum as mordants. The substrate used for the dyeing had a 25/75 hemp/cotton composition. The hemp raw material is an agricultural by-product that was subjected to mechanical and chemical treatments in order to cottonize the fibers, blend them with cotton, and thus obtain first 40-tex open-end yarns and then a knitted fabric. The latter was subjected to different dyeing conditions by varying the dye, mordant, and method for its application, type of water, and rinsing after dyeing. Measurements of the difference (¿E) and intensity (K/S) of color and fastness to washing and rubbing were carried out. The results showed that dyeing of a non-textile residual hemp substrate is possible, and that calendula is a good option for dyeing it with tap water, tannin-alum set in a meta-mordanting process, and rinsing after 24 h. In this way, a contribution has been made to the circular economy of the textile industry through the use of more sustainable sources and products, The authors gratefully acknowledge the financial support for this research from the Ministry of Science and Innovation of Spain (Project MAT2016-79352-R) and from the National Secretary of Higher Education, Science, Technology and Innovation of Ecuador (SENESCYT) for Doctoral Fellowship (No. CZ02-000926-2018), Objectius de Desenvolupament Sostenible::8 - Treball Decent i Creixement Econòmic, Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura, Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables, Objectius de Desenvolupament Sostenible::13 - Acció per al Clima, Objectius de Desenvolupament Sostenible::13 - Acció per al Clima::13.b - Promoure mecanismes per a augmentar la capacitat de planificació i gestió eficaces en relació amb el canvi climàtic als països menys avançats i als petits estats insulars en desenvolupament, centrats concretament en les dones, persones joves i comunitats locals i marginades, Postprint (published version)

El proyecto tiene como finalidad el poder medir con exactitud las propiedades de fricción de hilos de altas prestaciones que están en movimiento y en contacto con un sólido. En particular, el rozamiento a los que son sometidos en diferentes elementos de rozaduras que va sufriendo el hilo durante el proceso de trabajo en el proceso de extrusión, hilatura, y tisaje. Un factor que se a de tener en cuenta es que, las propiedades de fricción también afectan a la calidad y, a posteriori, al rendimiento de los hilos, seguidamente de los productos obtenidos. Como consecuencia, estudiaremos con detalle las tensiones optimas con sus respectivas velocidades, para a su vez, poder desarrollar una tabla que podrá ser usada como guía por empresas que quieran o desean tener información de cómo trabajan estos hilos o filamentos de grandes prestaciones. El propósito del proyecto es dar importancia y conocer las propiedades de fricción de los hilos textiles, en su forma dinámica de trabajo y en su comportamiento con diferentes tipos de superficies/materiales. Todos estos componentes de la industria textil, como los guía hilos son de interés general ya que tiene una directa relación con el rendimiento, las agujas de coser de las máquinas que están sometidas a tensiones por la fricción de las fibras, tejeduría en los telares ya que tienen que soportar cambios bruscos de tensiones y ángulos de trabajo. Estas dificultades nos permiten hacer un estudio más amplio para saber con exactitud el mejor régimen de trabajo del hilo, con objetivo de dar una mayor vida útil a las máquinas para tener mayores rendimientos y en consecuencia una mejor calidad del producto con menos perdidas de producción, velocidades de trabajos más adecuadas obteniendo así una mayor productividad para la empresa. Queremos obtener un estudio extenso, detallado en forma de guía a través de un manual especificado con una lista de material de hilos y filamentos detallando de forma clara, así teniendo un comportamiento en c

La producció de fibres de polièster ha estat present i en augment des de la seva sortida al mercat l’any 1951, sent una de les fibres amb major nombre d’aplicacions. Tot i les grans avantatges que ofereix, el procés d’obtenció, es dur a terme a partir de productes químics derivats del petroli o del gas natural. És per això que aquest projecte té com a objectiu l’estudi de la relació de la composició de teixits de polièster amb diferents percentatges de fibres de polièster verge i de polièster reciclat a la intensitat de color. S’han filat i teixit diverses mostres amb diferents percentatges de fibra reciclada i s’han sotmès a un procés de termofixat i una tintura per termosol amb les mateixes condicions. Finalitzat el procés, es sotmeten les mostres en el colorímetre i s’estudia les possibles variacions del color obtingut per determinar el possible afecte de les fibres de polièster reciclat en el resultat final. Addicionalment, també s’intentarà correlacionar la microestructura dels diferents fils amb el percentatge de fibres de polièster reciclada a partir d’un estudi diferencial d'escombrat. Amb els termogrames resultants, s’estudia la possible variància de propietats en funció del procés aplicat en la mostra i també en funció del percentatge de fibra reciclada de la mostra

La tendencia de los últimos años está siendo construir de una manera sostenibilista todo lo que nos rodea, incluso nuestra forma de vestir. Cada vez nos inclinamos más a cambiar el concepto “fast fashion” y optar por materiales que formen parte de unos parámetros sostenibles, es por eso que cada vez surgen nuevas ideas de cómo podemos reducir nuestro número de prendas que se consumen por habitante. En este sentido, gracias a los avances en investigación se han podido diseñar y producir armarios cápsula que en conjunción con la tecnología nos han aportado grandes ideas que pueden servir de punto de partida para que el sector se dirija hacia este tipo de modelo económico. Es importante poder dar un giro de 180 grados al modelo actual de economía que envuelve la industria de la moda, llevándola así hacia la economía circular. De esta manera, este trabajo propone la creación de un modelo de armario cápsula de estilo “street wear” basado en el uso de materiales sostenibles. Además, también se ha fijado la premisa que los diseños de las prendas resultantes se puedan adaptar a cuerpos y situaciones de manera modular, es decir, se ha priorizado la funcionalidad y adaptabilidad en la conceptualización de la colección. Por otro lado, una de las fibras más consumidas mundialmente es el poliéster PET, una fibra sintética derivada de fuentes no renovables. Las propiedades textiles más destacadas del poliéster son: gran elasticidad, resistencia ante roturas y roce, impermeabilidad, poco peso, resiste a los tintes, etc. En la búsqueda de fibras que puedan suponer una alternativa sostenible a las mencionadas y provengan de recursos renovables aparecen las fibras de ácido poliláctico (PLA). Las fibras de PLA son fibras que provienen del almidón del maíz (recurso renovable) y que además son biodegradables y biocompatibles. Es por este motivo que se ha elegido como materia prima las fibras de PLA para la creación de la mencionada colección. Así pues, se crearán unos diseños sostenible

Postprint (published version)

The ease of cultivation, structure and properties of hemp (Cannabis sativa L.), provide it a great potential for industrial applications; nevertheless, the unfavourable high content of lignin complicates its processing, especially in the textile area. An appropriate knowledge of the delignification process would lead to treat hemp fibres as cotton fibres. In this work, hemp has been treated chemically with an alkaline bath with sodium hydroxide [1M], liquor ratio 1/15, during different times at 110 °C. Then, the content of lignin of the treated fibres was determined with the methodology of Tappi T222 om-15 standard and subsequently, the samples were analysed by thermogravimetry (TGA). Through the correlation analysis, the relationship between lignin content, onset temperature of cellulose decomposition and loss of mass of the different decomposition steps were found. Finally, the kinetics of alkaline hemp delignification by using the residual lignin after chemical treatments, and the kinetics of the different decomposition steps was determined, Postprint (published version)

Raw hemp fibres are alkaline delignified at different times in order to evaluate the effect of time of delignification on moisture uptake behaviour of hemp. Lignin content of samples is measured. Samples of original and delignified hemp are subjected to moisture absorption/desorption isotherms from 5% to 95% of relative humidity at 25ºC and moisture uptake behaviour is assessed through measuring the sorption ratio of delignified vs. original hemp. Hysteresis makes evident the greater influence of lignin in moisture binding at lower relative humidities, while at higher humidities cellulose plays the most important role. GAB, Hailwood-Horrobin and Dent models are fitted to absorption/desorption isotherms. Delignification decreases the size of the monolayer that depends on the way it has been measured: Size measured in desorption is always greater than that in absorption. Lignin greatly contributes to the growth of the size of the monolayer. The energy constants of the monolayer differ according to the used model: results of delignified fibre in absorption are higher than those of the original ones while the contrary occurs in desorption. Lignin causes great differences between absorption and desorption. The energy constants of the multilayer are identical for the three models showing greater range of variation in delignified samples than in the original ones. Results in absorption are higher than those in desorption. The level of relative humidity at which primary moisture uptake ties with the secondary one is determined and it has been observed that decreases with the energy constant of the multilayer, while primary and secondary regain at this level show a strong relationship with the size of the monolayer and growths with them, Postprint (author's final draft)

Postprint (published version)

Authors gratefully acknowledge the financial support for this research from the Ministry of Science and Innovation of Spain (Project MAT2010-20324-CO2-01) and from the National Secretary of Higher Education Science Technology and Innovation of Ecuador (SENESCYT) for Master’s Fellowship (No. 2015-AR2Q8981). Also, authors would like to thank to the companies ANTEX, S.L. and La Seda de Barcelona for providing the different polyester pellets and, Clariant for providing the dispersing agents and to IQAP Masterbatch Group S.L. for the production of the hybrid multifilaments., Peer Reviewed, Postprint (published version)

The purpose of this project was to get a better understanding of the delignification kinetics of the enzyme laccase with the mediator HBT (Hydroxybenzotriazole) on hemp and lignin as a substrate. The end goal was to find the ideal ratio of enzyme/ HBT/ substrate. In addition, a bleaching process was done on the same pre-treatment hemp as that of the enzyme treatment. The first step was the pre-treatment of the hemp. With the last step of the pre-treatment, the chemical delignification through an alkaline treatment. The hemp before and after the alkaline treatment are tested trough the lignin determination test, FTIR and TGA. These tests gave good results where it was clear that this process indeed partly delignifies the hemp but also removes other constituents in the process. The following step was to determine the effect of the enzyme laccase, HBT and laccase together with HBT on two different alkaline treated hemps. After the reaction, an UV-vis spectroscopy was done on the liquor of the reactions and the percentage of lignin left from the pure lignin samples were determined. After that, the lignin content in the treated hemp samples was also determined. The found results gave an unchanged lignin percentage in the hemp samples. After the lignin determination test, the lignin received from this test was put under an FTIR spectrometer. In the pure lignin there was a drop in the amount of lignin left but not in an expected way. It was decided not to work any further on this section in this project. In the end, a bleaching process with H2O2 was done on the two same alkaline treated samples. On these bleached samples, a DP test was done. On a few selected samples an FTIR and TGA were also performed. The bleaching process gave interesting results but more research needs to be done to get a better understanding of what exactly is happening towards the hemp in the bleaching process., Incoming

The influence of the alkaline delignification of hemp on its moisture uptake has been studied under the project “Preparation and functionalization of hemp for textile substrates” focussed on the reduction of cotton imports for the manufacturing of clothing, household textiles and medical devices. The project looks for the partial replacement of cotton by hemp on the production of natural cellulosic textiles. Hemp fibres are alkaline delignified at different times to evaluate its effect on their moisture uptake behaviour to evaluate the ability of replacing cotton in the next-to-skin goods manufacturing. The paper gives three easy tools to analyse the moisture uptake behaviour by determining the sorption ratio, the hysteresis and the parameters of the isotherms fitted using three different models (GAB, Hailwood-Horrobin and Dent) to the absorption desorption isotherms. The samples of the original and delignified hemp have been subjected to moisture absorption/desorption trials from 5% to 95% RH at 25 º C. Sorption ratio and hysteresis reveal the greater influence of lignin on moisture uptake at low relative humidities, while at high, was cellulose which plays the most important role. The models fitted to the isotherms show that delignification decreases the size of the monolayer that, in desorption results always greater than in absorption. The energy constants of the monolayer for delignified fibres in absorption were higher than those for the original fibres, while the opposite occurred in desorption. Lignin caused great differences between absorption and desorption. The energy constants of the multilayer show a greater range of variation in delignified samples than in the original one, and results in absorption were higher than those in desorption. Delignification time of 3 h reached the highest cellulose content which best approached to the cellulose content of cotton causing that the moisture uptake behaviour drew near to it, especially at higher relative humidi, Postprint (published version)

Hemp (Cannabis sativa L.) is a plant of which, its ease of cultivation, structure and properties, provide it great potential for industrial applications; nevertheless, the unfavorable content of lignin complicates its processing, especially in the textile area. Thus, an appropriate knowledge of the delignification process would lead to treating hemp fibers as cotton fibers. In this work, hemp has been treated with an alkaline liquor [NaOH 1¿M] at 110¿°C during different times and afterwards, the substrates were chemically characterized in order to determine their lignin content and also analyzed by thermogravimetry (TGA). Through the correlation analysis, the relationship between lignin content, onset temperature of cellulose decomposition and loss of mass at the different decomposition steps were established. A hyperbolic kinetic model to explain the influence of alkaline treatment time on lignin content and also on the loss of mass at the four steps of decomposition of the samples by TGA up to 600¿°C has been developed. Although it has been found that the degradation of lignin occurred across the entire temperature range, results have shown that the influence of treatment time has become clearly relevant on lignin content, Step2 (180.5¿°C-273.5¿°C) where a fraction of 10 to 16% of lignin was degraded, and Step3 273.5¿°C-396.5¿°C) where cellulose was mainly decomposed and 20% of lignin was also degraded, Authors gratefully acknowledge the financial support for this research from the Ministry of Science and Innovation of Spain (Project MAT2016-79352-R) and from the National Secretary of Higher Education, Science, Technology and Innovation of Ecuador (SENESCYT) for Doctoral's Fellowship (No. CZ02-000926-2018), Postprint (author's final draft)

Raw hemp fibers are alkaline delignified to evaluate the effect of lignin on themoisture uptake behavior of hemp. Samples are subjected to moisture absorp-tion/desorption isotherms from 5% to 95% relative humidity at three differenttemperatures (15, 25, and 35 C). The sorption ratio between delignified anduntreated hemp is lowered by 25%. Hysteresis makes evident the greater influ-ence of lignin on moisture binding at low relative humidity while at highrelative humidity, cellulose plays the most important role. The GAB,Hailwood-Horrobin and Dent models are fitted to absorption/desorptionisotherms. Delignification and temperature decrease the size of the monolayer.The energy constants of the monolayer differ according to the model used.Lignin causes great differences between absorption and desorption. The greaterthe temperature is, the lower the monolayer energy constant. The energy con-stants of the multilayer are identical for the three models, showing a greaterrange of variation in delignified samples than in the untreated samples. Basedon primary and secondary energy constants, bonding enthalpies are determined.Estimations in desorption show higher correlation coefficients with the energyconstants, which enables to conclude that measures in desorption better explainthe effect of delignification on the water uptake behavior of hemp, Postprint (published version)

La falta de material de protección frente al COVID-19 afecta de forma alarmante a los profesionales de la salud, pero también a los cuidadores de personas mayores, profesionales de la limpieza, alimentación, transporte, fuerzas del orden, etc. Los equipos de protección individual (EPI) que deben utilizarse para COVID19 son, principalmente, las mascarillas, las gafas, los guantes y la ropa de protección, siendo esta última en la que nos vamos a centrar en este artículo, Postprint (author's final draft)

Thermal processing properties are a key factor in the industrial processing industry. The obtaining of a PET-based hybrid composite multifilament with textile properties (yarns) is presented. The system is composed by ceramic silicon carbide (SiC) nanoparticles and a dispersing agent included in a PET matrix. With the objective to produce a suitable nanocomposite, the study is divided in three parts: (i) evaluation by non-isothermal crystallization of three different dispersing agents (two of them based on esters of montanic acids and, the other on an amide wax) to achieve an homogeneous nanocomposite; (ii) study of the influence of the concentrations of SiC and of the more suitable dispersing agent on the thermal properties of the PET-hybrid composite; and (iii) the obtaining of a PET-hybrid multifilament with textile properties together with its characterization by Gel Permeation Chromatography (GPC), Differential Scanning Calorimetry (DSC) and mechanical properties, Postprint (author's final draft)

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Poly(ethylene terephthalate) (PET) has been mixed with fluorite (CaF2) particles to obtain micro- and nanocomposites aiming to obtain a hybrid multifilament. In first term, the use of two montanic waxes and an amide wax as dispersing agents towards the compatibilization of the inorganic and organic components of the CaF2/PET composite were considered. To do this, non-isothermal crystallization studies by differential scanning calorimetry have been carried out. Moreover, the influence of the CaF2 particle size and concentration on the thermal properties of the system have been also studied by this technique. Finally, the extrapolation of the results has materialised as a novel PET/CaF2 hybrid multifilament. Thermal and mechanical properties and molecular weight of the multifilament have been as well evaluated, Postprint (author's final draft)

La sustitución del uso del algodón por el cáñamo conlleva un sinnúmero de ventajas medioambientales y económicas. Debido a su ubicuidad, su cultivo con reducidos requerimientos de pesticidas y agua y, a características propias de la fibra, se ha convertido en una alternativa sostenible para su uso en el campo textil. El objetivo de este trabajo es la optimización del proceso de algodonización del cáñamo para la obtención de fibras con la máxima finura posible, con el fin de de reemplazar al algodón en la fabricación de productos textiles, Postprint (published version)