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UPCommons - E-prints UPC Universitat Politècnica de Catalunya (75,324 recursos)
E-prints UPC cobreix dues finalitats: per una banda, és el dipòsit institucional de la UPC que recull els articles de revista, les comunicacions de congrés i els reports de recerca generats en les activitats de recerca del personal docent i investigador de la universitat; per l'altra, és una eina que permet accelerar la producció científica, allotjant versions de documents prèvies a la publicació en una revista o a les actes d’un congrés.

Articles de revista

Mostrando recursos 1 - 20 de 120

1. Colour change of polyester dyed fabric during washing by ecological surfactants - Carrión Fité, Francisco Javier
Alkyl polyglucosides (APGs) have appeared on the market, offering good levels of biodegradability and ecotoxicity. These nonionic surfactants, obtained from natural substances, are 100% biodegradable and very suitable for washing. They are highly soluble, only slightly sensitive to electrolytes and rarely influenced by water hardness. This paper analyses the behaviour of APG and linear alkyl sulfonate, separately and in mixtures of different proportions, in order to show how dyed polyester fabric changed colour during washing and how dye transfers to white textile items (diacetate, polyamide, cotton, acrylic and wool). Before this process, the polyester was dyed with disperse dyes. Disperse...

2. Influence of special clays as builder in ecological detergents - Carrión Fité, Francisco Javier
The aim of this work is to determine the influence of certain clay micro particles added to detergent formulation to act as builders in removal of impurities (detersive power) during the washing of a standard cotton fabric (EMPA), and also to determine the whiteness of the fabric and its softness after washing. Sepiolite was used separately and together with bentonite, in the forin of micro partides. Bentonite is held to have a softening effect on cotton. A whitener was added to the detergent formulations to compensate for a possible effect of diminished whiteness in the washed fabric. Scanning electron microscope...

3. Cellulosic fiber reinforced cement-based composites: a review of recent research - Ardanuy Raso, Mònica; Claramunt Blanes, Josep; Toledo Filho, Romildo Dias
In the last few years, an increase in interest has been given to the use of cellulose fibers as alternatives for conventional reinforcements in composites. The development of commercially viable environmentally friendly and healthy materials based on natural resources is on the rise. In this sense, cellulosic fibers as reinforcements for cement mortar composites constitute a very interesting option for the construction industry. This paper presents a review of the research done during the last years in the area of the cement-based composites reinforced with cellulose fibers. The fibers used, processing methods, mechanical behaviour and durability are presented. The main...

4. Cellular structure and mechanical properties of starch-based foamed blocks reinforced with natural fibers and produced by microwave heating - López-Gil, Alberto; Silva-Bellucci, Felipe; Velasco, Daniel; Ardanuy Raso, Mònica; Rodríguez-Pérez, Miguel Ángel
The cellular structure and mechanical properties in compression of starch-based foams filled with natural reinforcements, such as grape wastes, cardoon wastes and barley straw fibers, have been studied in this work. The foams were produced by a microwave foaming process in which water is the plasticizer and at the same time the blowing agent. The use of thermoformed sheets as solid precursors for foaming allowed the production of foamed blocks with cells elongated in the expansion direction and with better properties in terms of rigidity and strength than foams produced in previous works by microwave heating of pellets. Moreover, the...

5. Corona plasma modification of polyamide 66 for the design of textile delivery systems for cosmetic therapy - Labay, Cedric Pierre; Canal Arias, José Ma; Navarro Sentanyes, Antonio; Canal Barnils, Cristina
Cosmetic and medical applications of technical textiles are a research expanding field. One of the added values of these new materials would be that they are suitable to contain and release active ingredients in a controlled manner. The influence of the initial state of the surface of polyamide 6.6 (PA66) fibers on the wetting properties of the fibers as well as on the incorporation of caffeine on the fibers and on its release kinetics from the fibers has been investigated. Comparison between industrially-finished PA66 fabrics and laboratory washed fabrics has been done to carry out this study. Furthermore, surface modification...

6. Application of microcapsules in spinning - Marsal Amenós, Félix
A new method has been developed for applying microcapsules in the spinning process, in all yarns made on ring spinning machines, whether short fiber or long fiber. The microcapsules were placed in the interstices of the yarn, before twisting. This solves the problem of permanence of the effect provided by the active ingredients contained in the microcapsule, for functionality and use of textile garments, against repeated washing. The method is technically and industrially feasible. This has been demonstrated by the interest shown by an important manufacturer of spinning machinery. The proposed method is valid for all types of fibers that...

7. Effect of surface treatment of titanium dioxide nanoparticles on non-isothermal crystallization behavior, viscoelastic transitions and cold crystallization of poly(ethylene terephthalate) nanocomposites - Cayuela Marín, Diana; Cot Valle, María Ana; Riva Juan, Mª del Carmen; Sanchez Leija, Regina Janete; Sanchez Loredo, Maria Guadalupe; Algaba Joaquín, Inés María; Manich Bou, Albert M.
The effect of untreated and tri-n-octylphosphine oxide (TOPO) surface-treated TiO2 nanoparticles when included as filler in poly (ethylene terephthalate) on its compatibility, non-isothermal crystallization behavior, viscoelastic transitions and cold crystallization has been studied. The effectiveness of the surface treatment has been studied using infrared spectrophotometry (FTIR) and thermogravimetric analysis (TGA). The effect of the untreated and surface-treated nanofiller content in the polymer, added by an extrusion process, on the non-isothermal crystallization has been studied by differential scanning calorimetry (DSC). The influence on the viscoelastic transitions and cold crystallization of PET nanocomposites has been studied through thermomechanical analysis (TMA). The surface...

8. A critical comparison of methods for the analysis of indigo in dyeing liquors and effluents - Buscio Olivera, Valentina; Crespi Rosell, Martin; Gutiérrez Bouzán, María Carmen
Indigo is one of the most important dyes in the textile industry. The control of the indigo concentration in dyeing liquors and effluents is an important tool to ensure the reproducibility of the dyed fabrics and also to establish the efficiency of the wastewater treatment. In this work, three analytical methods were studied and validated with the aim to select a reliable, fast and automated method for the indigo dye determination. The first method is based on the extraction of the dye, with chloroform, in its oxidized form. The organic solution is measured by Ultraviolet (UV)-visible spectrophotometry at 604 nm....

9. Strategies to improve the mechanical properties of starch-based materials: plasticization and natural fibers reinforcement - López Gil, Alberto; Rodríguez Pérez, Miguel Ángel; de Saja, José Antonio; Bellucci, Felipe Silva; Ardanuy Raso, Mònica
Biodegradable polymers are starting to be introduced as raw materials in the food-packaging market. Nevertheless, their price is very high. Starch, a fully biodegradable and bioderived polymer is a very interesting alternative due to its very low price. However, the use of starch as the polymer matrix for the production of rigid food packaging, such as trays, is limited due to its poor mechanical properties, high hidrophilicity and high density. This work presents two strategies to overcome the poor mechanical properties of starch. First, the plasticization of starch with several amounts of glycerol to produce thermoplastic starch (TPS) and second,...

10. Estudi de la composició de les mostres de teixit dels enterraments de la fossa de la Basílica dels Sants Màrtirs Just i Pastor de Barcelona - Carrera Gallissà, Enric
Postprint (published version)

11. Characterization and treatments of oil palm frond fibers and its suitability for technical applications - Ventura Casellas, Heura; Morón Soler, Moises; Ardanuy Raso, Mònica
The aim of this paper is to explore the potential of oil palm frond fibers (OPFf) for technical applications such as composite reinforcement. For this purpose, fibers obtained from frond wastes were subjected to various chemical treatments with NaOH and chemically and morphologically characterized. Afterward, composites of poly-lactic acid matrix and nonwoven matts made with the treated and the untreated OPFf were prepared and the mechanical properties tested. It was found that the alkaline treatment was effective for increasing the wettability of the fibers leading to composites with a good-balanced between lightness and toughness for potential applications in packaging or...

12. An improved TCF sequence for biobleaching kenaf pulp: influence of the hexenuronic acid content and the use of xylanase - Andreu Terrén, Glòria; Vidal Lluciá, Teresa
Enzymatic delignification with laccase from Trametes villosa used in combination with chemical mediators (acetosyringone, acetovanillone and 1-hydroxybenzotriazole) to improve the totally chlorine-free (TCF) bleaching of kenaf pulp was studied. The best final pulp properties were obtained by using an L-HBT-QPo sequence developed by incorporating a laccase-mediator stage into an industrial bleaching sequence involving chelation and peroxide stages. The new sequence resulted in increased kenaf pulp delignification (90.4%) and brightness (77.2%ISO) relative to a conventional TCF chemical sequence (74.5% delignification and 74.5% brightness). Also, the sequence provided bleached kenaf fibers with high cellulose content (pulp viscosity of 890 g . mL...

13. Gallic acid vehiculized through liposomes or mixed micelles in biofunctional textiles - Marti Gelabert, Meritxell; Martínez Rodríguez, Vanessa; Lis Arias, Manuel José; Valldeperas Morell, José; de la Maza, Alfons; Parra Juez, José Luis; Coderch Negra, Luisa
Liposomes and mixed micelles were used to vehiculize gallic acid, as antioxidant, when applied to different textiles designed to be in contact with the skin as biofunctional textiles. Foulard and bath exhaustion processes were assayed without the use of a binder. Liposomes with the antioxidant encapsulated were applied to cotton, polyamide, polyester, acrylic, and wool, using bath exhaustion and the pad-dry process. Higher absorption was obtained with bath exhaustion than with the pad-dry process for all fabrics. Liposome application to the different textiles showed an adequate substantivity for most fibers. However, the high desorption of most synthetic acrylic and polyester fibers confirmed the preferential application of...

14. Autoclaved cellulose fibre reinforced cement: effects of silica fume - Fernández Carrasco, Lucía; Claramunt Blanes, Josep; Ardanuy Raso, Mònica
With the aim of developing vegetable-fibre cement composites free of portlandite and with short curing process, this study analyses the influence of the curing conditions and the addition of pozzolanic material on the hydration of Portland cement–fibre matrices. Different specimens of cement composites with and without cellulose fibres and with and without silica fume were cured using autoclaving steam and normal curing. The hydration products and the microstructure of the resulting pastes were analysed by means of FTIR and BSE–SEM and the degree of hydration was quantified with Image analysis. The results indicate that the hydration products and the hardness...

15. Effects of needling parameters on some structural and physico-mechanical properties of needle-punched nonwovens - Ventura Casellas, Heura; Ardanuy Raso, Mònica; Capdevila Juan, Francisco Javier; Cano Casas, Francesc; Tornero García, José Antonio
The main objective of this paper is to study the effects of the processing parameters of the needle-punching machine and the interactions between them on some physico-mechanical properties of interest of nonwoven (NW) fabrics. For this purpose, a fractional factorial design has been planned with two levels for each factor: feeding speed, delivery speed, stroke frequency, penetration depth and gap between plates. Sixteen NW fabrics were obtained from polyester fibre and characterized by tensile strength and stiffness for mechanical behaviour and air permeability as physical properties of interest in some technical applications. The results have been subjected to statistical analysis...

16. Structural insights on laccase biografting of ferulic acid onto lignocellulosic fibers - Rencoret, Jorge; Aracri, Elisabetta; Gutíerrez, Ana; Del Rio, Jose C.; Torres López, Antonio Luis; Vidal Lluciá, Teresa; Martínez, Ángel T.
Treatment of high-kappa sisal pulp with Trametes villosa laccase and ferulic acid resulted in strong increases of kappa-number and acid-group content due to biografting of this phenolic acid, as shown by pyrolysis in the presence of tetramethylammonium hydroxide. The coupling linkages were investigated by 2D NMR of the lignin isolated from pulps. The aromatic region of the spectra showed incorporation of the cinnamic molecule, representing similar to 4% of the lignin content, that according to the displacement of its olefinic C-13(beta)-H-1(beta) signal to 117.0/6.40 ppm would be C-4-etherified. The aliphatic region of the spectra showed that ferulic acid also incorporates...

17. Influence of the dye transfer inhibitors for the washing of softened cotton fabric - Carrión Fité, Francisco Javier
In this, work the performance of several dye transfer inhibitors (DTI) copolymers (PVP, PVNO and PVNO with PVP) was tested for use as DTIs in washing softened undyed cotton fabric, in the presence of a direct dye in the washing bath, with and without water hardness. Three direct dyes were tested: red, blue and yellow. The detergent used was composed of an LAS anionic surfactant and a non-ionic fatty alcohol ethoxylate surfactant with 7¿m. OE, both separately and in the different molar proportions anionic with non ionic, at a total concentration of 5¿×¿10-3¿ M, and in the presence of zeolite...

18. Sonochemically processed cationic nanocapsules: Efficient antimicrobials with membrane disturbing capacity - Fernandes, Margarida M.; Francesko, Antonio; Torrent Burgués, Juan; Carrión Fité, Francisco Javier; Macedo Fernandes, Margarida Maria; Tzanov, Tzanko; Heinze, Thomas
Bacterial-mediated diseases are a major healthcare concern worldwide due to the rapid spread of antibiotic-resistant bacteria. One strategy to manage the bacterial infections while avoiding the emergence of resistant strains implies specific targeting and disruption of bacteria membranes. This work evaluates the potential of nanostructured biopolymer derivatives, nanocapsules (NCs), to disrupt the bacteria cell walls and effectively kill planktonic microorganisms. Two biopolymers, chitosan and cellulose, were chemically modified to synthesize derivatives with improved cationic character (thiolated chitosan and aminocellulose) prior to their processing into nanocapsules via a one-step sonochemical process. The interactions of NCs, displaying an average size of around...

19. Effect of texturing on porosity and critical dissolution time of polyamide 6.6 multifilaments - Cayuela Marín, Diana; Maillo Garrido, Josefina; Morales, C; Manich, Albert M.
The anomalous behaviour of polyamide 6.6 fibres textured by false twist to different physico-chemical techniques (as the critical dissolution time, CDT), compared with those obtained in polyester fibres, was attributed to a cracking of the. surface and/or to an increase in fibre porosity. This cracking appears when original fibre is treated at high temperature and it is due to the breakage of the skin/core structure of polyamide 6.6. This cracking has been demonstrated by the determination of drying kinetics in a thermogravimetric test that has been developed for this fibre

20. Preparation and characterization of cellulosic fibre-reinforced polypropylene foams - Ardanuy Raso, Mònica; Sousa Pais Antunes, Marcelo de; Velasco Perero, José Ignacio
The preparation and characterization of cellulosic fibre-reinforced polypropylene composite foams is presented. The cellulose fibres were isolated from a barley straw obtained from local sources. They were compounded with the polymer in the melt state to obtain composites with nominal concentrations of 10 and 20% by weight. After compression-moulding the composite samples were foamed in a high-pressure batch-process employing CO2 as foaming agent. The effects of the fibre loading on the basics characteristics of the foams was investigated

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