<p>The varieties of paint are today very big, but many of the more popular paints are less than environmental friendly. The uses of fossilized fuel in paints are common because these paints dry fast and are color true. It would be beneficial for the environment if more renewable source were used to produce paint. Linseed oil is an old base for oil paints. It is renewable and easily procured. But linseed oils have some aspects that give it a bad reputation. There are problems with the slow drying and the color turning yellow when exposed to darkness for long periods of time. Researchers at KTH have connected the yellowing to linolenic acid, one of the common fatty acids in linseed oil (Svensson, M. Johansson, M, Stenberg, C. Samuelsson, J. 2003). Hempseed oil is also a drying oil like linseed, but hempseed oil contains a larger amount of the fatty acid linoleic acid and a smaller amount of linolenic acid (http://en.wikipedia.org/wiki/Hempseed_oil). This might mean that oil paint based on hempseed-oil instead of linseed-oil might have fewer problems with yellowing.Experiments with the two oils have been executed side by side in order to compare results. Two oil paints have also been produced and tested. Test pieces painted with the two different oil paints were exposed to moisture, daylight and complete darkness and then compared.</p>

This study describes the mechanical response of thermoset polymers under high compressive loads. The study is divided into two parts. The first part focuses on the behaviour of a powder coating when used in a clamping force joint and how the properties vary when the chemical and physical structure of the coating is changed. The second part discusses the fundamental understanding of the behaviour of thermoset polymers with small thickness-to-width ratio subjected to compressive stresses, the aim being to develop mathematical material models for viscoelastic materials under high compressive loads. In the first part polyester powder coatings were used with variations in molecular weight, number of functional groups of the resin, amount and type of filler and thickness of the coating. The coatings were subjected to conventional tests for coatings and polymers and also to specially designed tests developed to study the behaviour of powder coatings in clamping force joints. The high compressive loads in a clamping force joint put high demands on the relaxation and creep resistance of the coating and the study shows the importance of crosslink density, filler content, and also coating thickness in order to achieve the desired mechanical properties of a coating. A high reactivity of the resin, facilitating a high crosslink density and hence a high Tg, is the most important property of the coating. A film with high crosslink density shows increase in relaxation time and in apparent yield strength under compression, and also an increase in relaxation modulus and storage modulus in tension at temperatures above Tg. Addition of fillers reduces the deformation during compression and tension, but also induces a lower strain at break and hence a more brittle coating. The reinforcing effect of the fillers is pronounced when increasing the crosslink density of the coating, especially in the compression tests. The effect is evident in compression even at low amounts of fillers, where the relaxation time and resistance to deformation are strongly increased. The combination of high crosslink density and addition of fillers is therefore desirable since fillers then can be used moderately in order to achieve a reinforcing effect in compression while minimising embrittlement. The study also showed that increased coating thickness will give rise to defects in the coating, especially voids and blisters due to evaporation of water formed during the curing of the polyester powder coating. These defects will give rise to stress concentrations and increased plastic deformations in the coating, impairing the properties of the clamping force joint. The results from relaxation tests in tension were used to create a micromechanical model. This model was used in finite element modelling to estimate the loss of clamping force in a screw joint and to correlate with the experimental results of the powder coatings. In the second part of the study a well-defined free radically cured vinyl ester resin was used and studied in six different geometries in order to determine the dependence of apparent mechanical properties on the particular size and shape of a sample when it is subjected to high compressive loads. Variation of the specimen thickness, boundary conditions and loading conditions reveals that the geometry of the sample has a significant effect on the mechanical performance of the polymer. The apparent modulus and the yield strength increase dramatically when the thickness-to-width ratio of the sample is reduced, whereas they decrease when the friction between the sample and the compression plate is reduced. The creep strain rate decreases when the thickness of the material is reduced and it decreases even more when the amount of material surrounding the compressed part of the sample is increased. Creep and strain recovery tests on large specimens were used to develop a mathematical model including non-linear viscoelastic and viscoplastic response of a thermoset vinyl ester. The model was used in FEM calculations where the experimental results were compared with the calculated results in order to model the trends of the material response when varying the sample geometry. / QC 20100921

The varieties of paint are today very big, but many of the more popular paints are less than environmental friendly. The uses of fossilized fuel in paints are common because these paints dry fast and are color true. It would be beneficial for the environment if more renewable source were used to produce paint. Linseed oil is an old base for oil paints. It is renewable and easily procured. But linseed oils have some aspects that give it a bad reputation. There are problems with the slow drying and the color turning yellow when exposed to darkness for long periods of time. Researchers at KTH have connected the yellowing to linolenic acid, one of the common fatty acids in linseed oil (Svensson, M. Johansson, M, Stenberg, C. Samuelsson, J. 2003). Hempseed oil is also a drying oil like linseed, but hempseed oil contains a larger amount of the fatty acid linoleic acid and a smaller amount of linolenic acid (http://en.wikipedia.org/wiki/Hempseed_oil). This might mean that oil paint based on hempseed-oil instead of linseed-oil might have fewer problems with yellowing.Experiments with the two oils have been executed side by side in order to compare results. Two oil paints have also been produced and tested. Test pieces painted with the two different oil paints were exposed to moisture, daylight and complete darkness and then compared.

Detta examensarbete är utfört på Möbelsnickeriprogrammet på Carl Malmsten - Centrum för Träteknik och Design i Stockholm. Om man som Möbelsnickare har ambitionen att utveckla och förnya hantverket är det nödvändigt att ha kunskap och kännedom om historiens hantverkstekniker och material. Intarsia, att med tunna träfaner skapa dekorativa mönster och motiv på möbler, är ett typexempel på en sådan teknik. I historien var det genom intarsian som tekniken att färga faner utvecklades. Vilka metoder och material använde man sig av förr? Hur kan en genomfärgningsprocess se ut idag? Hur kan genomfärgat material användas i ett modernt sammanhang? Kan genomfärgat faner vara ett verktyg för att utveckla intarsian och skapa något nytt inom möbelhantverket? Dessa är en del av de frågor som hanteras i rapporten. Syftet med examensarbetet är att undersöka vilken metod och vilka material som är mest lämpliga för att genomfärga faner i mindre skala. Genom studier och samtal med lärare och hantverkare hämtas fakta om vilka material och metoder som användes förr. Med denna kunskap som grund utförs experiment med ett antal utvalda färgämnen för att finna en lämplig metod. Förekommande svårigheter som uppstod under experimenten är att faneren inte helt penetreras av färglösningen eller att färgen inte är den önskvärda. Det kunde dock konstateras att om faneren dränkes under en viss tid i en spritlöslig färgblandning åstadkommes ett gott resultat. Med kunskap om hur faner genomfärgas formges en produkt där det färgade materialet används i en intarsia, Ett antal bilder fungerar som inspirationsmaterial och motivet ritas med utgångspunkten att det skall vara nyskapande och samtida. Resultatet av arbetet är en beskrivning i hur man genomfärgar faner och visar hur detta kan gå till i praktiken. Dessutom diskuteras möjligheterna att använda ett sådant material för att förnya och utveckla hantverkstekniken intarsia. / This exam work is executed at the fine woodworking course at Carl Malmsten – Center for Wood Technology and Design in Stockholm. If you as a cabinetmaker and fine woodworker have the ambition to renew and develop the craft, it is necessary to have knowledge of and insights in traditional techniques and materials. Marquetry, the use of thin wood veneer to create patterns and motives in furniture, is such a technique. In history, it was through marquetry that the technique to dye and stain veneers was developed. Which methods and materials were used in those days? What can a process of dying through veneers look like today? How can dyed-through material be used in a modern context? Can it be used as a tool to develop marquetry and create something new within the woodcraft? These are a few of the questions that are discussed in this work. The purpose of the exam work is to examine which method and materials are most suitable for this dying-through process on a smaller scale. By studying and interviewing teachers and craftsmen, facts were gathered about methods and materials that are used traditionally. With this knowledge a series of experiments are performed with different selected dyestuffs to find a suitable method. Some difficulties that occurred during these experiments were that the solution did not penetrate the veneers fully and that the colour was not the expected one. However, the conclusion was that if the veneers were drenched in a solution of spirit based dyestuff for a certain time span the result was sufficient. With the knowledge of how to dye-through veneer a product is designed where the dyed material is used in a marquetry motif. A series of images work as a source of inspiration and the resulting motif is contemporary and modern in design. The result of the exam work is a description of how to dye-through veneer and shows how this can be performed in a practical situation. Furthermore, the possibilities of using this material, in order to renew and develop the art of marquetry, are explored.

No description available.

<p>Detta examensarbete är utfört på Möbelsnickeriprogrammet på Carl Malmsten - Centrum för Träteknik och Design i Stockholm. Om man som Möbelsnickare har ambitionen att utveckla och förnya hantverket är det nödvändigt att ha kunskap och kännedom om historiens hantverkstekniker och material. Intarsia, att med tunna träfaner skapa dekorativa mönster och motiv på möbler, är ett typexempel på en sådan teknik.</p><p>I historien var det genom intarsian som tekniken att färga faner utvecklades. Vilka metoder och material använde man sig av förr? Hur kan en genomfärgningsprocess se ut idag? Hur kan genomfärgat material användas i ett modernt sammanhang? Kan genomfärgat faner vara ett verktyg för att utveckla intarsian och skapa något nytt inom möbelhantverket? Dessa är en del av de frågor som hanteras i rapporten.</p><p>Syftet med examensarbetet är att undersöka vilken metod och vilka material som är mest lämpliga för att genomfärga faner i mindre skala. Genom studier och samtal med lärare och hantverkare hämtas fakta om vilka material och metoder som användes förr. Med denna kunskap som grund utförs experiment med ett antal utvalda färgämnen för att finna en lämplig metod. Förekommande svårigheter som uppstod under experimenten är att faneren inte helt penetreras av färglösningen eller att färgen inte är den önskvärda. Det kunde dock konstateras att om faneren dränkes under en viss tid i en spritlöslig färgblandning åstadkommes ett gott resultat.</p><p>Med kunskap om hur faner genomfärgas formges en produkt där det färgade materialet används i en intarsia, Ett antal bilder fungerar som inspirationsmaterial och motivet ritas med utgångspunkten att det skall vara nyskapande och samtida.</p><p>Resultatet av arbetet är en beskrivning i hur man genomfärgar faner och visar hur detta kan gå till i praktiken. Dessutom diskuteras möjligheterna att använda ett sådant material för att förnya och utveckla hantverkstekniken intarsia.</p> / <p>This exam work is executed at the fine woodworking course at Carl Malmsten – Center for Wood Technology and Design in Stockholm. If you as a cabinetmaker and fine woodworker have the ambition to renew and develop the craft, it is necessary to have knowledge of and insights in traditional techniques and materials. Marquetry, the use of thin wood veneer to create patterns and motives in furniture, is such a technique.</p><p>In history, it was through marquetry that the technique to dye and stain veneers was developed. Which methods and materials were used in those days? What can a process of dying through veneers look like today? How can dyed-through material be used in a modern context? Can it be used as a tool to develop marquetry and create something new within the woodcraft? These are a few of the questions that are discussed in this work.</p><p>The purpose of the exam work is to examine which method and materials are most suitable for this dying-through process on a smaller scale. By studying and interviewing teachers and craftsmen, facts were gathered about methods and materials that are used traditionally. With this knowledge a series of experiments are performed with different selected dyestuffs to find a suitable method. Some difficulties that occurred during these experiments were that the solution did not penetrate the veneers fully and that the colour was not the expected one. However, the conclusion was that if the veneers were drenched in a solution of spirit based dyestuff for a certain time span the result was sufficient.</p><p>With the knowledge of how to dye-through veneer a product is designed where the dyed material is used in a marquetry motif. A series of images work as a source of inspiration and the resulting motif is contemporary and modern in design.</p><p>The result of the exam work is a description of how to dye-through veneer and shows how this can be performed in a practical situation. Furthermore, the possibilities of using this material, in order to renew and develop the art of marquetry, are explored.</p>

This thesis addresses the potential for use of cobalt(III) complexes for functionalisation of lightly oxidised iron surfaces. In Chapter 2 the preparation of cobalt(III) complexes of a series of ligands based on 1,1,1-tris(aminomethyl)ethane is described. The synthesis was approached in two ways. Firstly, preparation of functionalised triol molecules as precursors to functionalised triamine ligands was investigated. This approach utilised the Tollens condensation of aldehydes with formaldehyde. In a second approach, the functionalisation of tetrakis(aminomethyl)methane in which one amine arm has been differentiated was used. The tetraamine was reacted with benzaldehyde and reduced with borohydride ion to give a secondary amine molecule that was then functionalised using alkyl or aryl sulfonyl chloride molecules. Chapter 3 describes the measurement of the binding of some cobalt(III) complexes to the surface of high surface area goethite. It was observed that complexes that have three exchangeable ligands bind more strongly than those with two exchangeable ligands. This is rationalised as being due to there being more bonds to the surface formed by complexes with three exchangeable ligands. It was also observed that complexes with three exchangeable ligands give greater surface coverage than those with two. This is likely due to the larger cross sectional area of the complexes with two exchangeable ligands in comparison to that of those with three, which blocks potential adjacent sites. Preliminary experiments on the use of the contact angle, SEM, EDS and QCM to characterise complex binding are explored in Chapter 4 . The results from the EDS and QCM experiments show that these may be valuable tools for measuring this binding and the subsequent surface properties, but have not yielded detailed results at this point. In Chapter 5 the use of cobalt(III) complexes as inhibitors of corrosion of iron in hydrochloric acid is investigated. All the complexes tested, even those that showed no binding to goethite surfaces, inhibit the corrosion to some degree. The level of inhibition is dependent on the complex, with [Co(tren)Cl2]Cl showing maximum inhibition of 81% and [Co(tame)Cl3] showing maximum inhibition of 53%. For some of the complexes, their concentration in solution over the course of the experiment was monitored by UV-vis. It was found that the complex disappears in a zero order reaction, the rate of which is dependent on the complex. However, the exact nature of this reaction is unknown. Furthermore, it was observed that inhibition of corrosion continues after the complex is no longer observed in solution. There is a difficulty in rationalising the inhibition being dependent on the complex identity, but not its continued presence in solution. Consequently, the mechanism of corrosion inhibition that explains all of these observations is still not known.

La presente tesis doctoral ha sido desarrollada en el departamento de Química Física de la Universidad de Alicante y pretende profundizar en la síntesis de materiales semiconductores y de co-catalizadores, y en el estudio de sus aplicaciones en procedimientos fotoelectroquímicos conducentes a dispositivos que realicen la fotosíntesis artificial. En concreto, se pretende diseñar fotoelectrodos que permitan la fotodisociación del agua prestando una atención particular al uso de determinados co-catalizadores que funcionen sobre la superficie de dichos fotoelectrodos y que incrementen la velocidad de los procesos redox de generación de hidrógeno y de oxígeno. La radiación solar aporta a nuestro planeta unos 120000 TW de energía cada año, una cantidad que es superior al consumo tecnológico realizado por el hombre en cuatro órdenes de magnitud. Por tanto, y debido a la creciente demanda de energía a nivel mundial, resulta interesante la idea de intentar abordar la problemática energética actual desde el punto de vista de la conversión y acumulación fotoquímicas de energía solar. Esta estrategia permitiría solucionar, además, los graves problemas medioambientales causados por el consumo de combustibles fósiles, que continúan siendo la fuente mayoritaria de energía en la actualidad. En este contexto, el hidrógeno supone una de las alternativas a los combustibles fósiles más prometedoras y sostenibles. De hecho, como combustible, el hidrógeno destaca por su alta densidad energética y porque su combustión no libera compuestos de carbono perjudiciales para el medio ambiente. En un escenario en el que los métodos tradicionales para obtener hidrógeno puro se enfrentan a grandes desafíos, el agua se presenta como una fuente ideal de dicho gas, abundante y libre de los dañinos gases de efecto invernadero que de otra forma surgen como subproductos. La fotoelectrólisis del agua sobre electrodos semiconductores, que consiste en dividir dicha molécula en sus componentes (oxígeno e hidrógeno) requiere la aplicación de electricidad desde una fuente externa y el uso de electrocatalizadores adecuados para romper los enlaces químicos. El primer estudio sobre este tema fue publicado por Fujishima y Honda en el año 1972, quienes describieron una célula fotoelectroquímica para la disociación del agua en oxígeno e hidrógeno constituida por un fotoánodo de dióxido de titanio y un contraelectrodo de platino. Sin embargo, todavía no se ha conseguido desarrollar un sistema fotoelectroquímico de estas características que ofrezca eficiencias y estabilidad realmente competitivas. La elección y desarrollo de materiales electródicos fotoactivos (fotoánodo y fotocátodo) es una de las variables que condicionan de manera determinante ambos factores. Entre las características principales que deben cumplir los materiales semiconductores para actuar como fotoánodos o fotocátodos destacan las siguientes: (i) transporte eficiente de carga eléctrica, (ii) posición favorable de las bandas de valencia y conducción para inducir las reacciones de reducción y oxidación del agua, (iii) buena absorción de la luz visible (lo que implica un valor de anchura de banda prohibida de entre 1.9 y 3.1 eV), (iv) elevada estabilidad química tanto en medio acuoso como bajo condiciones de iluminación, con el fin de asegurar una larga vida útil de los dispositivos, y (v) bajo coste económico. Aunque los óxidos semiconductores son los materiales más prometedores dentro de este ámbito, todavía no se ha identificado ningún material semiconductor que cumpla con todos estos requisitos con el que se pueda llevar a cabo la fotodisociación del agua de manera eficiente: muchos tienen una anchura de banda prohibida demasiado grande o muy pequeña o son inestables en medios acuosos. Entre las diferentes estrategias encaminadas a conseguir aumentar la eficiencia de los procesos de generación de oxígeno y de hidrógeno sobre electrodos semiconductores, destaca su modificación superficial con partículas de electrocatalizador (conocidas como co-catalizadores) que sirvan para mejorar la transferencia de portadores de carga fotogenerados y limitar su recombinación, y disminuir los sobrepotenciales para las reacciones de generación de oxígeno e hidrógeno. De hecho, para facilitar una reacción eficaz, dichos co-catalizadores deben poseer una alta durabilidad, una elevada actividad catalítica y una gran área superficial. El platino es muy eficiente para la electrocatálisis, pero su elevadísimo precio (superior a los 30.000 dólares por kilogramo) y su poca abundancia hace inviable su uso comercial a gran escala. Por todo ello, surge la necesidad de explorar nuevas vías más factibles que permitan llevar a cabo la electrocatálisis de estos procesos redox y que, en base a las últimas investigaciones realizadas, pueden pasar por ciertos hidróxidos metálicos, nitruros, fosfuros, sulfuros y carburos de determinados elementos de transición. En este contexto, los principales objetivos de la presente tesis doctoral son los siguientes: - Sintetizar diferentes electrodos semiconductores nanocristalinos o policristalinos compactos de óxidos ternarios de la familia ABO4 y de la familia perovskita (ABO3) mediante técnicas de síntesis por sol-gel, para su uso posterior como fotoánodos o fotocátodos en procesos de disociación fotoelectroquímica del agua. - Caracterizar desde el punto de vista electroquímico y fotoelectroquímico los diferentes fotoelectrodos sintetizados para evaluar su actividad como fotoánodos o fotocátodos en procesos de disociación fotoelectroquímica del agua. - Sintetizar diferentes hidróxidos metálicos del grupo del hierro (Fe, Co y Ni) mediante una técnica de síntesis por baño químico, para su uso posterior como electrocatalizadores para la reacción de generación de oxígeno en medio alcalino y como co-catalizadores de la reacción fotoelectroquímica de generación de oxígeno sobre los fotoánodos obtenidos. - Caracterizar desde el punto de vista electroquímico y fotoelectroquímico los diferentes hidróxidos metálicos preparados para evaluar su actividad como electrocatalizadores para la reacción de generación de oxígeno en medio alcalino y como co-catalizadores de la reacción fotoelectroquímica de generación de oxígeno sobre los fotoánodos obtenidos con el fin de mejorar las propiedades fotoelectroquímicas de los mismos y potenciar así su aplicabilidad en procesos de disociación fotoelectroquímica del agua. - Sintetizar partículas metálicas (fundamentalmente, de Ni), mediante una técnica de síntesis por electrodepósito, que puedan ser empleadas como co-catalizadores de la reacción fotoelectroquímica de generación de hidrógeno sobre los fotocátodos obtenidos con el fin de mejorar las propiedades fotoelectroquímicas de los mismos y potenciar así su aplicabilidad en células de fotosíntesis artificial. También se contempla la posibilidad de generar una capa pasivante/extractora de TiO2 entre la superficie del fotocátodo y el depósito de co-catalizador que favorezca la actividad de este. -Caracterizar los fotoelectrodos y los electrocatalizadores preparados estructural, composicional y morfológicamente mediante técnicas de difracción de rayos X, técnicas espectroscópicas (espectroscopía de absorción ultravioleta-visible, espectroscopía fotoelectrónica de rayos X y espectroscopía Raman), y técnicas de microscopía (microscopía electrónica de barrido y de transmisión). El desarrollo de estos objetivos, los resultados correspondientes y las conclusiones obtenidas se exponen en detalle en once capítulos relacionados. El Capítulo I consiste en una introducción donde se presentan los principios físicos y electroquímicos básicos de los semiconductores y se presenta el estado del arte de los diferentes materiales utilizados a lo largo de esta tesis. En el Capítulo II se revisan las diferentes técnicas de síntesis y caracterización empleadas en esta investigación. Los Capítulos III a X están específicamente dedicados al desarrollo de los objetivos antes mencionados relacionados con la preparación y caracterización de fotoelectrodos, electrocatalizadores y co-catalizadores. Es importante señalar que los Capítulos III a VI se han publicado en revistas indexadas, mientras que los resultados mostrados en los Capítulos VII a X ya se han enviado o se enviarán para su publicación en un futuro próximo. Finalmente, en el Capítulo XI se recogen las conclusiones generales y específicas de esta tesis. / La realización de la presente tesis doctoral ha sido financiada por el Ministerio español de Educación, Cultura y Deporte mediante una ayuda para la Formación de Profesorado Universitario (FPU15/02005).

<p>The aim of this study was to explore environmentally friendly solutions to reduce the friction present in automotive transmissions.</p> <p>A 2005 Ford Escape Hybrid transmission was used in this study to establish reasonable operating conditions for the gear surfaces.</p> <p>Background on gear operation and surface interaction was studied to understand the nature of the contact between the gear surfaces. Based on this, a mathematical model of gear interaction was developed and used to bracket the loading conditions of the gear tooth interface to be up to 1.5GPa of contact pressure with 2m/s relative sliding velocity. This information was used to aid in the identification of suitable surface engineering technologies and set the operating conditions for reciprocating tribometer based measurements.</p> <p>Additionally, tribological tests were performed on pin-on-disc samples which were treated with various surface treatments. The resulting wear surfaces were then studied using optical and Scanning Electron Microscopy (SEM) as well as Raman Spectroscopy. These techniques were used to better understand the mechanisms associated with wear and the role that the surface treatments played in reducing wear. Based on the testing performed, the best surface treatment for this application was a super finishing process. This process also met cost and environmental constraints. An in-house dynamometer was also developed to be used in the future full scale testing of a transmission.</p> / Master of Applied Science (MASc)

<p>The papermaking industry uses a large amount of starch each year, both as a wet-end additive and as a rheological modifier in surface sizing and coating colors. It is important to be able to reduce the amount of chemicals used in the papermaking and surface treatment process, to reduce costs and to make the process even more efficient. Interest in new high-performance starches is great. By using these new types of starches, improved recycling of barrier products may be obtained as well as a reduction in the use of synthetic sizing agents. The objectives of this work were to understand the behavior of temperature-responsive hydrophobically modified starches, where the solubility in water simply can be adjusted by temperature or by polymer charge, to improve the barrier properties, like the water vapor permeability, mechanical properties and water resistance (Cobb and contact angle) of papers surface sized by starch-containing solutions, and to investigate the potential for industrial use of these temperature-responsive starches. It was demonstrated that the temperature-responsive starches phase separate upon cooling and, depending on the charge density of the starch, a particulate precipitation or a gel-like structure was obtained. The starch with zero net charge showed a larger increase in turbidity than the starch with a cationic net charge, indicating that particulate precipitation is favored by a zero net charge and that the formation of a gel network is favored by charged starch molecules. Further, the starches formed inclusion complexes with surfactants, giving stabilization to the starches in the presence of surfactants. The net charge density of the starch and the charge of the surfactant determined whether or not an inclusion complex would form between them. Important mechanisms for the stability of the starch seemed to be formation of mixed micellar-like structures between the hydrophobic chain of the starch and the surfactant along the starch backbone in addition to formation of inclusion complexes between the starch and the surfactant. The hydrophobically modified starches showed higher hydrophobic surface character when applied to the paper surface above the critical phase separation temperature than with application at room temperature. Free films of the temperature-responsive starches showed good barrier against oxygen, but no barrier against water vapor. The mechanical properties decreased with addition of glycerol to the films.</p>