http://hdl.handle.net/2117/3783 2013-06-18T22:38:32Z http://hdl.handle.net/2117/19524 Title: Tara (Caesalpinia spinosa): the sustainable source of tannins for innovative tanning processes Authors: Castell, Joan Carles; Sorolla, Silvia; Jorba, Montse; Aribau, Joaquim; Bacardit Dalmases, Anna; Ollé Otero, Lluís Abstract: This study considers the fruit of the tara tree as a sustainable source for tanning agents and proposes alternatives to the commercial mineral salts and vegetable extracts to comply with environment and social concerns. Tara tannins have been used in retanning formulas in leather processing and its properties are well known. This work aims to optimize formulations using tara as a pre-tanning agent. Combinations with a naphthalene sulphonic syntan are used to obtain an innovative wet-white recipe in which shrinkage temperature, tensile strength, tensile elongation, tear load and lightfastness properties are considered as statistical variables 2013-06-06T11:11:26Z http://hdl.handle.net/2117/19495 Title: Development of nanocomposites with antibacterial effect for leather and textile Authors: Bacardit Dalmases, Anna; Casas, Concepció; Bou Serra, Jordi; Rocas, Josep; Ollé Otero, Lluís Abstract: The aim of this work is to develop new systems of nanocomposites to confer new functions to materials used for seats of public vehicles and public spaces. Specifically, this study focuses on antibacterial effect for leather and technical textile substrates. The first stage of the research consists of a selection of micro/nanomaterials and active principles: selection and evaluation of nanoparticles, antibacterial and antifungal substances. In the second stage, the process of encapsulation of active principles was studied. The research includes optimization of the encapsulation process by improving the size and stability of the capsules. In addition, the synthesis of a hybrid organic-inorganic polymer acting as a nanomaterial carrier was developed. To understand the mechanisms of synthesis and action of micro/nanomaterials, characterization techniques have been used: scanning electron microscopy SEM and optical microscopy, analysis and distribution of particle size (DLS, Zetasizer). Regarding the antibacterial and antifungal ability of nanocomposites, we adapted standard ASTM 2180-07 "Test methods for determining the activity or incorporated antimicrobial agent (s) in polymeric or hydrophobic materials." Different products have been developed and the results obtained allow us to conclude that the synthesized products showed inhibition to the growth of bacteria and fungi on the contact surface 2013-06-04T11:10:54Z http://hdl.handle.net/2117/17584 Title: Determination of fungicides in residual tanning floats using solid phase micro extraction Authors: Font Vallès, Joaquim; Reyes Reyes, Maria; Cuadros, Sara; Bacardit Dalmases, Anna; Ollé Otero, Lluís; Marsal Monge, Agustín Abstract: Solid-phase microextraction (SPME) was optimized for extraction of the leather preservative agents 2-(thiocyanomethylthio)-benzothiazole (TCMTB), 4-chloro-3-methylphenol (PCMC), 2-phenylphenol (OPP), 2-Octyl-3(2H)-isothiazolone (OIT), 2-mercaptobenzothiazol (MBT) and 3-iodo-2-propynyl-butylcarbamate (IPBC) in spent tanning floats. Determination was carried out by high performance liquid chromatography (HPLC) with photo diode array detection (PDA). The following parameters were studied to achieve the maximum efficiency in extraction: fiber type, adsorption conditions (extraction time, ionic strength, temperature) and desorption parameters (time, temperature and composition of the desorption solvent). Results indicate that SPME using a 60um polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber is appropriate for the extraction of these types of compounds. Recoveries ranged from 82% to 116% with RSDs between +-8% and +-12% and limits of detection below 1 mg/L except for IPBC. The optimized procedure was successfully applied for the determination of leather preservatives in eleven residual tanning floats taken from different companies. This method enables us to determine quantitatively the fungicides contained in th residual floats. Consequently, it will constitute a very useful tool to improve the preservative uptake in leather manufacturing processes 2013-02-05T15:48:08Z http://hdl.handle.net/2117/17583 Title: GREDIQ-RIMA: The evolution of a teaching project of experimentation in chemistry Authors: Grau Vilalta, Maria Dolors; Guaus Guerrero, Ester; Martínez Martínez, María del Rosario; Calvet Tarragona, Aureli; Farran Marsà, Adriana; Salán Ballesteros, Maria Núria; Álvarez del Castillo, María Dolores; Gorchs Altarriba, Roser; Almajano Pablos, María Pilar; Morillo Cazorla, Margarita; Garrido Soriano, Núria Abstract: Authors of this project belong to the Resources Chemistry Teaching Group (GReDiQ) involved in RIMA (Research and innovation in learning methodologies). The audiovisual and multimedia material productions realized have been grouped into three themes: Basic Techniques of Experimentation in Chemistry, Safety in Chemistry Laboratories and Advanced Techniques of Experimentation in Chemistry. This work has been awarded a prize of the Universitat Politècnica de Catalunya (UPC–BARCELONATECH), one of the Autonomous Region of Catalunya and another one of a State scope 2013-02-05T15:33:21Z http://hdl.handle.net/2117/17102 Title: Isocyanate toughened pCBT: reactive blending and tensile properties Authors: Abt, Tobias Martin; Martínez de Ilarduya Sáez de Asteasu, Domingo Antxon; Bou Serra, Jordi; Sánchez Soto, Miguel Abstract: Cyclic butylene terephthalate oligomers (CBT) were reacted in a ring-opening polymerization with three types of isocyanates: a bifunctional aromatic type, a bifunctional aliphatic type and a polymeric aromatic isocyanate. All reactions took place in a batch mixer. The use of 0.5 to 1 wt% isocyanate led to a dramatic increase in elongation at break of polymerized cyclic butylene terephthalate (pCBT), from 8 to above 100%. The stiffness and strength of the modified pCBT, however, were found to slightly decrease. Proton nuclear magnetic resonance (NMR) analysis shows that the formation of thermally stable amide groups is the dominant chain extension reaction mechanism. Gel content measurements suggest a linear structure for samples containing bifunctional isocyanates while pCBT modified with polyfunctional isocyanate exhibited some gel formation at higher isocyanate content. Melting and crystallization temperatures as well as degree of crystallinity were found to decrease with increasing isocyanate content. No phase separation was detected by scanning electron microscopy (SEM) analysis. Moreover, a high degree of polymerization is deduced due to the absence of CBT oligomer crystals. Description: Electronic version of an article published as "Express polymer letters" vol. 7, nº. 2, February 2013, p. 172-185. <http://www.expresspolymlett.com/> 2012-12-11T15:45:30Z http://hdl.handle.net/2117/16427 Title: Determinación de TCMTB y otros fungicidas en piel Authors: Reyes Farrera, María R.; Font Vallès, Joaquim; Bacardit Dalmases, Anna; Marsal Monge, Agustín Abstract: La norma ISO 13365:2011 desarrolla un método analítico para la determinación del contenido de los agentes conservantes 2-(tiocianometiltio)-benzotiazol (TCMTB), 4-cloro-3-metilfenol (PCMC), 2-fenilfenol (OPP) y 2-octil-3(2H)-isotiazolona (OIT) en cuero por cromatografía líquida. La determinación simultanea de los fungicidas TCMTB, PCMC, OPP, OIT, y también de 2-mercaptobenzothiazol (MBT) y 3-yodo-2-propinil-butilo (IPBC) en muestras de piel se llevó a cabo mediante cromatografía líquida (HPLC) con detector ultravioleta de fotodiodos (PDA). La preparación de la muestra y el proceso de extracción se realizaron siguiendo la norma ISO 13365. La fase móvil consistió en agua con un 0.1% de ácido fórmico (A) y acetonitrilo con un 0.1% de ácido fórmico (B). En la detección cromatográfica se introdujo un pequeño cambio en relación con la norma. Se utilizó un detector de fotodiodos en lugar de un detector de longitud de onda fija para mejorar la fiabilidad de las identificaciones y la sensibilidad de la cuantificación. Se ha comprobado que el 2,4,6-triclorofenol (TCP) y el pentaclorofenol (PCP) no interfieren en la determinación. Las fortificaciones de 30 y 300 mg/kg en cuero produjeron unas recuperaciones medias de TCMTB del 94% y 99%, respectivamente. Las recuperaciones de los otros fungicidas fueron similares. Los fungicidas investigados se determinaron en 40 muestras de cueros del mercado. En el 90% de las muestras se encontraron residuos de TCMTB. En resumen, la nueva norma ISO 13365:2011 proporciona un método rápido y fiable, no sólo para la determinación de las cuatro moléculas incluidas en el ámbito de aplicación de la norma, sino también para otros fungicidas como el IPBC y el MBT 2012-09-04T16:42:12Z http://hdl.handle.net/2117/16140 Title: Determination of penetration and fixation curves of leather using humic derivatives Authors: Bacardit Dalmases, Anna; Shendrik, Alexander; Morera Prat, Josep Maria; Bou Serra, Jordi; Ollé Otero, Lluís Abstract: This study examines the behavior of three different types of humic acids (natural humic acids, regenerated humic acids, and sulphited humic acids) with regard to their penetration and fixation to the leather. More specifically, through the tests carried out the curves of penetration and fixation were drawn, and from these the optimum pH intervals of penetration and fixation to the leather were determined. The data obtained is essential in view of the subsequent application of humic acids as tanning agents and/or retanning agents 2012-06-26T14:27:04Z http://hdl.handle.net/2117/16014 Title: La encuesta SEEQ como instrumento de mejora continuada: aplicaciones en diferentes contextos universitarios Authors: Corral Manuel de Villena, Ignacio de; Almajano Pablos, María Pilar; Domingo Peña, Joan Abstract: El proceso de cambios en el que estamos inmersos los universitarios hace que debamos estar atentos a los distintos retos que se nos plantean. Una forma global de planificar este cambio es a partir de criterios de calidad implícita y explícita. Para ello en nuestro caso, nos hemos propuesto desde hace años utilizar instrumentos tradicionales para que sea posible un rediseño y una revisión constante de los resultados de la calidad de nuestra docencia focalizado en términos del aprendizaje alcanzado por nuestros estudiantes. La utilización de la encuesta SEEQ (Students' Evaluation of Educational Quality), y la misma, pero algo modificada, nos ha permitido disponer del elemento clave para esta reconstrucción constante de la asignatura con el objetivo de mejorarla permanentemente. Los resultados de mejora alcanzados en estos años nos animan a perseverar en su uso a la vez que nos permiten mostrar evidencias de que este tipo de encuestas constituye una eficaz herramienta para poder disponer de datos frente a terceros y planificar, ejecutar, ver los resultados y revisar de forma permanente nuestro cometido docente. 2012-06-11T14:18:27Z http://hdl.handle.net/2117/15982 Title: Study of the effect of temperature, relative humidity and UV radiation on chrome-tanned leather ageing Authors: Bacardit Dalmases, Anna; Jorba, Montse; Font Vallès, Joaquim; Ollé Otero, Lluís Abstract: Since leather is strongly affected by three main environmental parameters: temperature, relative humidity and UV radiation, this piece of research focuses on the effect that these three factors have on chrome-tanned leather ageing. Chrome tanned leathers were exposed to weathering effects in a climatic chamber in order to identify the most important variables affecting this weathering process and also to check for any possible interactions. Both a multilevel centralized factorial experimental design and an analysis of variance (ANOVA) were used as statistical tools for estimating the effects of the parameters 2012-06-07T15:37:22Z http://hdl.handle.net/2117/15919 Title: Curtición vegetal con extracto de semilla de uva Authors: Ramon Arcal, Salvador; Bacardit Dalmases, Anna; Font Vallès, Joaquim; Ollé Otero, Lluís Abstract: El objetivo de este trabajo es estudiar la viabilidad de usar el extracto de semilla de uva procedente de subproductos de la industria vinícola, como fuente sostenible y renovable de taninos para curtir pieles vacunas al vegetal, frente a los extractos vegetales convencionales de quebracho, mimosa, castaño, gambier, o tara que provienen de arboles cultivados en zonas geográficas concretas. La substitución parcial en el proceso industrial de las tenerías de alguno de los extractos habituales por el de semilla de uva, contribuiría al esfuerzo por preservar la deforestación del planeta. Primero se comparan las características físicas de la piel vacuna curtida con un extracto único, para fabricar vaquetilla vegetal natural. Se evalúa el artículo obtenido y se controlan las resistencias a la tracción y al desgarro, alargamiento a la rotura, grueso, solidez a la luz, color y absorción de agua. También se realiza una cromatografía líquida de cada uno de los taninos usados. A continuación se realiza un “coupage” de extracto de semilla de uva con otros extractos comerciales para conseguir una vaquetilla con mejores prestaciones y se compara con productos comerciales presentes en el mercado de la marroquinería de alta calidad 2012-05-24T11:40:05Z http://hdl.handle.net/2117/15918 Title: Nuevas aplicaciones de la cromatografía iónica en el sector de curtidos Authors: Perez Quiñones, Carmen; Bacardit Dalmases, Anna; Ollé Otero, Lluís; Reyes Ferrera, Mª Reyes; Font Vallès, Joaquim Abstract: La industria de curtidos utiliza gran variedad de productos químicos en las diferentes etapas del proceso de curtición. Una parte de estos productos son absorbidos por las pieles, mientras que el resto pasan a las aguas residuales contribuyendo algunos de ellos al aumento de la salinidad. Muchos de estos productos químicos presentan un componente aniónico. En el contexto del control de calidad, los laboratorios del sector de curtidos tienen la necesidad de analizar especies aniónicas en diferentes muestras, tales como productos químicos, aguas residuales, baños de diferentes etapas y piel piquelada, curtida y acabada. En otros sectores, la tendencia actual en el análisis de aniones es el uso de técnicas sensibles y rápidas, como la cromatografía líquida de alta resolución. En este estudio se desarrollan métodos cromatográficos innovadores, con detección ultravioleta indirecta y directa, para la determinación simultánea de los principales aniones de interés en la industria de curtidos (cloruro, sulfato, nitrato, acetato, formiato, fosfato, nitrato, fluoruro y bromuro). Estos métodos se aplican a diferentes muestras. Se optimiza un método con cromatografía iónica y detección indirecta. La separación se realiza utilizando biftalato potásico como fase móvil. También se presenta un nuevo método cromatográfico simple, con detección ultravioleta directa y sulfato sódico como eluyente 2012-05-24T11:11:17Z http://hdl.handle.net/2117/15766 Title: Humic acid derivatives as tanning and retanning agents Authors: Bacardit Dalmases, Anna; Morera Prat, Josep Maria; Shendrik, Alexander; Jorge Sánchez, Juan; Ollé Otero, Lluís Abstract: This study examines the behaviour of three types of humic acids (natural humic acids, regenerated humic acids, and sulphited humic acids) with regard to their capacity to be used as tans and retans. The study makes use of conditions set out in a previous study (See Determination of penetration and fixation curves of leather using humic derivatives). Additionally, subsequent complementary tests were carried out using other retans that are commonly used in the tanning industry in order to compare and improve on the physical properties assessed here 2012-04-26T15:16:08Z http://hdl.handle.net/2117/15267 Title: Comparison of weathering variables on chrome-tanned and wet-white leather ageing Authors: Ollé Otero, Lluís; Jorba, Montse; Castell, Joan Carles; Font Vallès, Joaquim; Bacardit Dalmases, Anna Abstract: Leather is a natural material that can be used in different environments and often under aggressive environmental conditions that may cause premature ageing. The most important factors influencing the degradation of leather are temperature, relative humidity and UV radiation. Leathers with chrome tannage and wet-white leathers were exposed to weathering effects using a climatic chamber in order to identify the most important variables affecting this weathering process and to check for interactions. Both a multilevel centralized factorial experimental design and an analysis of variance (ANOVA) have been employed as statistical tools for estimating the effects of the parameters 2012-02-21T10:39:49Z http://hdl.handle.net/2117/14796 Title: Neuroprotective effects of white tea against oxidative Authors: Almajano Pablos, María Pilar; Vila, Ingrid; Ginés, Silvia Abstract: Tea is one of the most widely consumed beverages in the world and represents an important source of antioxidants mainly catechins that confer beneficial effects in reducing the risk of cardiovascular diseases, age-related disorders or cancer. In the central nervous system, oxidative stress caused by increased production of reactive oxygen and nitrogen species represents an important mechanism for neuronal dysfunction and cell loss in different neurodegenerative disorders. The neuroprotective effects of green-tea-derived polyphenols have extensively been demonstrated in different models of neurotoxicity. However, few data have been reported on the antioxidant activity of white tea extracts in the nervous system. In the present study, we demonstrate that white tea extracts protect striatal cell lines against oxidative stress-mediated cell death. The effects of white tea on protection of striatal cell cultures are likely associated with the antioxidant properties of white tea components since neuronal cell loss induced by nonoxidative insults such as D1 dopamine receptor activation cannot be prevented by pre-treatment with white tea. Altogether our results suggest that regular consumption of white tea may contribute to reduce oxidative stress associated with brain injury and be clinically useful for treating age-related and neurodegenerative disorders. 2012-01-25T11:51:47Z http://hdl.handle.net/2117/14556 Title: Synthesis of highly carboxylate acrylic resins for leather impregnation Authors: Ollé Otero, Lluís; Solé, M.M.; Shendrik, Alexander; Labastida, L.; Bacardit Dalmases, Anna Abstract: This work describes the synthesis of new leather finishing acrylic resins. Four resins ware synthesized varying the concentration of ethyl acrylate, and metracrylic acid. Sodium lauryl sulphate was used as emulsifying system. By means of an experimental design, an optimal resin for leather impregnation was defined. The results obtained indicated that the variation of the monomer concentration influences the resin properties, the hardness of the film, and the penetration into the leather. Most importantly, this new highly carboxylate acrylic resin enables leather impregnation without the use of surfactants or penetrating agents 2012-01-16T11:06:52Z