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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.

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

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

This work reports the conversion of a commercial polarization microscope (Zeiss Jenaval) into an automatized Mueller matrix microscope. A Mueller matrix measurement provides the value of all the optical properties of a specimen (linear dichroism, linear birefringence, circular dichroism etc.) at a specific wavelength. In contrast to traditional polarization microscopes, which use white light and crossed polarizers to generate colored interference patterns that are analyzed by the microscope user and give only semi-quantitative results, here we demonstrate that it is possible to convert a polarization microscope into a Mueller microscope by only adding two motorized rotating compensators into the optical path without altering the optics or other opto-mechanical elements of the microscope. To our knowledge this is the most compact, fast and handy Mueller microscope ever developed. The performance of this new Mueller matrix microscope is illustrated with some birefringence measurements on textile fibers Este trabajo describe la conversión de un microscopio de polarización comercial (Zeiss Jenaval) en un microscopio de matriz de Mueller automatizado. Una medida de la matriz de Mueller proporciona todas las propiedades ópticas de una muestra (dicroísmo lineal, birrefringencia lineal, dicroísmo circular, etc) para una longitud de onda dada. Los microscopios de polarización tradicionales usan luz blanca y polarizadores cruzados para generar un patrón de colores interferencia que debe ser interpretado por el usuario del microscopio y proporciona resultados sólo semi-cuantitativos. En este trabajo demostramos que añadiendo dos compensadores rotatorios actuados por sendos motores es posible convertir un microscopio de polarización en un microscopio de matriz de Mueller sin alterar la óptica u otros elementos opto-mecánicos del microscopio. Creemos que este es el microscopio de matriz de Mueller más compacto, rápido y práctico que se ha desarrollado. El funcionamiento de este microscopio se demuestra con algunas medidas de birrefringencia en fibras textiles

Polylactide (PLA) multifilaments, false-twist textured at different temperatures (135, 150 and 165ºC) and draw ratios (1.30, 1.35 and 1.40) have been stabilized by a continuous post setting treatment at 50 m/min and 100ºC using a specially designed chamber. The crystallinity of the original textured filaments and those of the stabilized ones has been measured. The effect of post setting on the thermomechanical behaviour according to the texturing conditions has been studied. The relationship between crystallinity and both relaxation shrinkage and maximum phase lag temperature have been pointed out

7 pages, 7 figures, 3 tables.-- Available online Oct 31, 2004., The determination of the effective temperature of the thermal treatment applied to polyester substrates in the textile process has been broadly studied by differential scanning calorimetry (DSC). In this investigation, the authors have studied the possibilities of the thermomechanical analysis (TMA) as a method for the determination of this temperature. For this purpose, fabrics of polyester heatset in an industrial plant between 160 and 210°C, have been analyzed by DSC and TMA. The good results obtained show the possibilities of this technique for the determination of the effective temperature of a thermal treatment., This paper is a part of the Project MAT-97 1186 granted by the Comisión Interministerial de Ciencia y Tecnología (CICYT) within the Materials Programme.

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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