Thickening Castor Oil with a Lignin-Enriched Fraction from Sugarcane Bagasse Waste via Epoxidation: A Rheological and Hydrodynamic Approach

Thickening vegetable oils to different extents is of great interest in the design and development of new bio-based lubricant formulations, as achieving a wide range of rheological properties is crucial to the successful replacement of petroleumbased traditional counterparts. With this aim, the influence of epoxidation degree, modified by altering the reaction conditions, on the viscous flow properties of epoxidized castor oil was investigated together with the incorporation of a lignin-enriched fraction from sugarcane bagasse waste to more extensively modify the rheological properties, thereby valorizing this waste fraction. Oil thickening was achieved by promoting the cross-linking between the epoxidized oil and the lignin-enriched fraction that enables the compatibilization of both components. Castor oil epoxidation was assessed by means of standard volumetric titration methods and infrared spectroscopy. In addition, a fully rheological characterization of both epoxidized and lignin-thickened castor oils was carried out. A hydrodynamic approach was also followed, aiming to provide an estimation of the Mark−Houwink−Sakurada parameters and relate the intrinsic viscosity with the average molecular weight of the resulting epoxidized castor oil/lignocellulose macromolecular compounds. The chemical interaction between castor oil and the lignocellulosic material increased as the extent of epoxidation was increased, yielding a variety of rheological responses from Newtonian liquids of increasing viscosities (from around 1 to 500 Pa·s) to viscoelastic liquids.This work is part of a research project (RTI2018-096080-B- C21) sponsored by the MICINN-FEDER I+D+i Spanish Programme. The financial support is gratefully acknowledged. The authors are also grateful to Dr. Ignacio Ballesteros (CIEMATMadrid, Spain) for kindly providing the ligninenriched waste fraction used in this study.Funding for open access charge: Universidad de Huelva / CBU

Pea Protein‑Based Bioplastics Crosslinked with Genipin: Analysis of the Crosslinking Evolution

Replacing conventional plastics with other products obtained from biobased and biodegradable raw materials is an increasingly studied solution. In this line, the development of protein-based bioplastics is a promising alternative. However, for some applications, such as packaging it would be necessary to improve their properties by including an additional stage to crosslink the protein chains during the production of bioplastics. Therefore, pea protein-based bioplastics crosslinked with genipin, a natural non-toxic chemical crosslinking agent, are evaluated in this study. The bioplastics are obtained via injection moulding and genipin, is included in the initial formulation. Specifcally, the concentration of genipin and the efects on the protein blends with genipin over days are evaluated. The evolution of the reaction is followed by the colour change of the blend, together with thermal analyses and infrared spectroscopy. Results showed the evolution of the crosslinking in the blends resulted in conformational changes that resulted in the modifcation of the initial yellowish colour to a blueish system. Respect their bioplastics, more deformable systems with a lower water absorption capability are obtained by using genipin as crosslinking agents This work is a part of a I+D+i PID2021-124294OBC21 project which is sponsored by MCIN/AEI/10.13039/501100011033/ and “ERDF A way of making Europe”. The authors thank their fnancial support. In addition, the authors would also acknowledge for the postdoctoral contract of Víctor M. Pérez Puyana from the “Contratación de Personal Investigador Doctor” supported by the European Social Fund and Junta de Andalucía (PAIDI DOCTOR – Convocatoria 2019-2020). Funding for open access publishing: Universidad de Sevilla/ CBUADepartamento de Ingeniería Química, Química Física y Ciencias de los Materiale

Characterization and production of agglomerated cork stoppers for spirits based on a factor analysis method

The decision-making in the investment of a new line of stoppers based on agglomerated cork requires knowledge of the composition and its contribution to its performance. For this, it is necessary to observe the leading products on the market and to test a series of prototypes with different formulations. The development of manufacturing products made by cork, such as bottle stoppers, benefits strongly from accurate chemical and structural characterizations, correlated to the final material performance. A wise starting point to fulfill such requirement consist of comparing available products in the market to be compared with different prototypes with varying composition. This work presents a blind characterization of a series of cork samples through a non-supervised exploratory analysis designed to select agglomerated corks for spirits and still wines in the packaging industry. A total of 18 batches, with 3 of them being high-end commercial products, were used to build 15 different prototypes. They were subsequently characterized with the exact composition of microgranulated cork as the unknown variable. Statistical results based on 14 parameters related to the physic-thermo-mechanical properties indicate that the suitability of selecting the stopper relies on the study of only 4 or 5 of the initial parameters. Hence, it is shown that a reduced number of parameters may be considered to properly describe the mechanical behavior of agglomerated cork, allowing the wise choice of the most convenient material for the intended application. The factorial map reveals that the only sample batch manufactured based on the tested prototypes correlates with the three of the products supplied by the competence.This work was funded by the Junta de Andalucía (Research groups INNANOMAT, ref. TEP-946 and TMA, ref. TEP-181). Co-funding from UE is also acknowledged. The authors wish to thank “TORRENT INNOVA, S.A.”. MdlM acknowledges the Juan de la Cierva postdoctoral fellowship from MICINN (IJCI-2017–31507)

A Mathcad‐based educational experience to address the design of nonisothermal plug flow reactors

Mathcad is a simple-to-use and intuitive mathematical software that helps students to minimize the mathematical difficulties involved in solving engineering problems. The design of nonisothermal plug flow reactors (PFR) is a fundamental issue within the field of chemical reaction engineering; however, its teaching–learning process is hindered by students' mathematical difficulties in solving ordinary differential equations. In this paper, the software Mathcad was conveniently integrated into an educational experience through the resolution of two real case studies. In the first one, a simple liquid-phase reaction is considered in a PFR working at different operating conditions, whereas the second case evaluates a PFR taking place multiple reactions (parallel reactions) with a heat exchanger attached. The assessment of this experience, which was held into two 5-h Mathcad workshops, revealed that Mathcad made the design of non-isothermal PFR more appealing, facilitated the understanding of the design process, and brought another dimension to the way the students perform complex calculations

Desarrollo de nuevos agentes espesantes y/o gelificantes de aceites vegetales a partir de diferentes fracciones lignocelulósicas modificadas químicamente mediante epoxidación

During the last decades, the world is really concerned about the pollution and the negative effects that most chemicals and/or end-used products are causing on the environment, especially those derived from crude oil. In this sense, the lubricant industry has also become more sensitive to the needs of the environment and it is fostering the replacement of non-renewable raw materials by others coming from natural resources. The first objective of this tendency was the substitution of mineral oils by other more eco-friendly lubricating base oils, by using vegetable oils or some derivatives, whose properties make them promising candidates to be employed as biodegradable lubricants. However, regarding lubricating grease formulations, these are generally composed of non-natural thickeners, like metallic soaps and poliureas, with the subsequent impact on the biodegradable characteristics of the final product. In this sense, in order to produce completely renewable and biodegradable lubricating grease formulations, there is an open research field aiming to find new bio-thickeners based on natural resources, whose characteristics provide suitable properties to the final biolubricating grease. With this aim, this work claims to develop biodegradable gellike dispersions constituted by a vegetable oil (castor oil) and chemically modified lignocellulosic materials able to act as efficient thickeners in these formulations to be applied as lubricating greases. Lignocellulosic materials such as lignin, which is considered a residual fraction of cellulose pulping and bioethanol production, with a great global manufacture; and cellulose pulp, composed of cellulose, hemicellulose and lignin, and constituting a renewable, abundant and inexpensive raw material for many applications, have been selected as biopolymers to replace the metallic soaps traditionally employed as thickeners in lubricating greases. For this purpose, these biopolymers have been chemically modified by using epoxy compounds, such as epichlorohydrin and glycidyl ether derivatives, by varying both the nature of the epoxide and the proportions used in the epoxidation reaction, and afterwards dispersing them into castor oil, in order to obtain physically stable chemical gels. With the aim of assessing the extent of the biopolymers epoxidation and the properties of resulting biolubricating greases, different characterization techniques have been used. Thus, epoxy index determination, infrared spectroscopy, thermogravimetric analysis and differential scanning calorimetry tests were carried out to verify the chemical modification of biopolymers. Moreover, oleogels were fully characterized from a rheological and tribological point of view, also studying the microstructure of some of them. In general, a higher epoxy index, i.e. a higher epoxidation degree of the lignocellulosic materials studied, improves the compatibility with castor oil and favours the physical stability of the resulting oleogels, as a consequent of the chemical cross-linking produced between the free epoxy groups and the hydroxyl groups of castor oil. These chemical interactions are also responsible for the final properties of these oleogels. Thus, more suitable rheological properties are obtained for their use as bio-lubricating greases when the lignin or cellulose pulp have a high epoxy index. The degree of modification of these lignocellulosic materials can be controlled by varying the conditions of the epoxidation reaction (temperature, time and proportion of reagents). On the other hand, the use of aromatic epoxides as modifying agents provides, in general, more convenient rheological and tribological properties compared to their aliphatic counterparts, for the same epoxidation degree of the lignocellulosic material, due to a higher level of cross-linking achieved in the three-dimensional network of chemical oleogels. In this way, the rheological behaviour of most oleogels developed was very similar to that found in traditional lubricating greases. On the other hand, the formulations thickened with epoxidized cellulose pulp show excellent thermal stability, without significant changes in rheological properties up to 150 ºC. In addition, both friction and wear, evaluated in a tribological contact, were reduced by introducing the biothickeners consisting of epoxidized lignocellulosic material in the formulations, in comparison to the castor oil as the sole lubricant. Overall, it may be concluded that all formulations synthetized from completely renewable materials, showed suitable properties to be proposed as promising alternatives to conventional lubricating greases.Durante las últimas décadas, se ha desarrollado una mayor concienciación sobre la contaminación y los efectos negativos que los diferentes productos químicos y/o de uso final ejercen sobre el medioambiente, especialmente aquellos que proceden del petróleo. En este sentido, la industria de los lubricantes ha aumentado también su sensibilidad sobre el impacto de estos materiales en el medioambiente y está intentando reemplazar el uso de materias primas no renovables por aquellas procedentes de fuentes renovables. El primer objetivo de esta iniciativa fue la sustitución de los aceites minerales por otras bases lubricantes amigables con el medioambiente, tales como aceites vegetales, o derivados de ellos, cuyas propiedades los convierte en candidatos prometedores como bases lubricantes biodegradables. Sin embargo, en relación con las formulaciones de grasas lubricantes, éstas, además, contienen generalmente espesantes no naturales, tales como jabones metálicos y poliureas, cuyo uso implica una reducción de las características biodegradables del producto final. De esta forma, y con objeto de producir formulaciones de grasas lubricantes completamente biodegradables y renovables, existe un campo abierto hacía la búsqueda de bio-espesantes basados en productos renovables cuyas características proporcionen las propiedades adecuadas al producto final. Con este objetivo, en este trabajo se pretende desarrollar dispersiones tipo gel biodegradables constituidas por un aceite vegetal (aceite de ricino) y materiales lignocelulósicos químicamente modificados que actúen como espesantes para su aplicación como grasas lubricantes. De este modo, materiales lignocelulósicos como la lignina, la cual está considerada un subproducto residual en la fabricación de la pasta de papel y producción de bioetanol, con una gran producción a nivel global; y la pasta de celulosa, compuesta por celulosa, hemicelulosa y lignina y que representa una materia prima renovable, abundante y asequible para muchas aplicaciones, han sido seleccionadas como biopolímeros para reemplazar los espesantes basados en jabones metálicos tradicionalmente empleados en grasas lubricantes. Con este propósito, se modificaron químicamente estos biopolímeros usando compuestos epoxídicos, tales como epiclorhidrina y derivados del glicidil éter, variando tanto la naturaleza del epóxido como la proporción utilizada en la reacción de epoxidación, y después se dispersaron en aceite de ricino con objeto de obtener geles químicos físicamente estables. Con el fin de evaluar el grado de modificación de los diferentes materiales lignocelulósicos y las propiedades de las grasas biolubricantes, se aplicaron diferentes técnicas de caracterización. Así, se realizaron ensayos de determinación del índice de epóxido, espectroscopía infrarroja, análisis termogravimétrico y calorimetría diferencial de barrido para verificar la modificación química de los biopolímeros. Además, se realizó una amplia caracterización reológica y tribológica de los oleogeles obtenidos, estudiando también la microestructura de algunos de ellos. En general, un mayor índice de epóxido, es decir un mayor grado de epoxidación de los materiales lignocelulósicos estudiados, mejoran la compatibilidad con el aceite de ricino y favorecen la estabilidad física de los oleogeles resultantes, como consecuencia del entrecruzamiento químico producido entre los grupos epóxidos libres y los grupos hidroxilos del aceite de ricino. Estas interacciones químicas son, por otra parte, las responsables de las propiedades finales de estos oleogeles. Así, se obtienen propiedades reológicas más adecuadas para su uso como grasa bio-lubricante cuando la lignina o la pasta de celulosa poseen un alto índice de epóxido. El grado de modificación de estos materiales lignocelulósicos puede controlarse variando las condiciones de la reacción de epoxidación (temperatura, tiempo y proporción de reactivos). Por otra parte, el uso de epóxidos aromáticos como agentes modificadores permite obtener, en general, propiedades reológicas y tribológicas más adecuadas en relación a las obtenidas utilizando epóxidos alifáticos, para el mismo grado de epoxidación del material lignocelulósico, debido a un mayor nivel de entrecruzamiento en la red tridimensional de los oleogeles químicos. De este modo, el comportamiento reológico de una gran parte de los oleogeles desarrollados fue muy similar al de las grasas lubricantes tradicionales. Por otro lado, las formulaciones espesadas con pasta de celulosa epoxidada muestran una excelente estabilidad térmica, sin cambios significativos en las propiedades reológicas hasta 150 ºC. Además, tanto la fricción como el desgaste, evaluados en un contacto tribológico, disminuyeron al introducir los bio-espesantes consistentes en material lignocelulósico epoxidado en las formulaciones, en comparación con el uso de aceite de ricino como único lubricante. Como principal resultado de esta investigación, puede concluirse que todas las formulaciones estudiadas y sintetizadas con compuestos procedentes de recursos completamente renovables, presentan propiedades adecuadas para ser propuestas como alternativas prometedoras a las grasas lubricantes convencionales

Innovative stearic acid-in-silicone oil (o/o) phase change material lubricating emulsions (PCMLEs): Thermo-rheological and tribological properties

This paper analyses the feasibility of using novel non-aqueous stearic acid-in-silicone oil (o/o) phase change material lubricating emulsions (PCMLEs). The novel use of these dispersions with heat storage capacity for lubricating applications can be considered a new approach since they have not yet been used for such purposes. In this study, PCMLEs consist of stearic acid, with a melting point of roughly 69 °C, as a dispersed phase change material in a continuous silicone oil medium. Samples were prepared by mixing different phase ratios, by high-shear processing and stabilised by a constant concentration of a silicone-based non-ionic surfactant. Taking into consideration the ability of stearic acid to absorb latent thermal energy during machinery operation, the potential application in lubrication has been assessed by means of stationary and temperature ramp friction tests. Moreover, the effect of the phase transition on the PCMLEs’ rheological response has been analysed through stationary flow tests and frequency sweeps within the linear viscoelastic range at constant temperatures, below (40 °C) and above (80 °C) the melting process of the disperse phase. Additionally, their thermal properties and morphology were also studied through X-ray diffraction measurements (XRD), differential scanning calorimetry (DSC) and polarised optical microscopy. As a result, the reported rheological properties and microstructure led to the enhancement in tribological characteristics of PCMLEs since a significant reduction in the friction factor is evidenced, within the whole temperature range, when compared to the silicone oil.Grant PID2020-116905RB-I00 funded by MCIN/AEI/10.13039/ 501100011033 and grant TED2021-131284B-I00 funded by MCIN/AEI/ 10.13039/501100011033 (Spain) and European Union “NextGenerationEU”/ PRTR. Clara Delgado and Adrián Tenorio also acknowledge financial support from Junta de Andalucía (Spain) through post-doctoral Grants DC 01228 (co-funded by the EU Fondo Social Europeo (FSE), European Union) and POSTDOC_21_00644, respectively. Funding for open access charge: Universidad de Huelva / CBUA (Spain).Departamento de Ingeniería Química, Química Física y Ciencias de los Materiale

Modification of Alkali Lignin with Poly(Ethylene Glycol) Diglycidyl Ether to Be Used as a Thickener in Bio-Lubricant Formulations

Considerable efforts are currently being made by the academic community and industry, aiming to develop environmentally friendly lubricants with suitable technical features for their performance. In this context, lignin could be considered a promising candidate to be used as a bio-sourced thickening agent to formulate eco-friendly lubricating greases. In this work, alkali lignin (AL) was chemically modified with poly(ethylene glycol) diglycidyl ether (PEGDE). Afterwards, the epoxidized lignin was properly dispersed in castor oil (CO) in order to obtain an oleogel for lubricant applications. The epoxidized lignins were characterized by means of epoxy index determination, thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The epoxide-functionalized lignin-based oleogels were analyzed from both rheological and tribological points of view. It was found that the viscosity, consistency and viscoelastic functions of these oleogels clearly increased with the epoxy index of the epoxide-modified lignin compound. Thermo-rheological characterization of these oleogels revealed a slight thermal dependence of the viscoelastic moduli below 100 °C, but a significant softening above that critical temperature. In general, these oleogels showed low values of the friction coefficient under the mixed lubrication regime as compared to the neat castor oil

Assessment of Lignin Residues from Bioethanol Production of Olive Stones as Green Chemical Thickener of Epoxidized Linseed Oil

This work focused on the characterization of lignin residues from bioethanol production of olive stones (OS) and the use of these residues to chemically thicken epoxidized linseed oil (ELO). OS were processed by an acid/steam explosion pretreatment, followed by pre-saccharification, using different enzyme dosages, and simultaneous saccharification and fermentation. The chemical composition of the OS lignin residues was analysed, revealing a high lignin content (66.6–69.5%), and lower quantities of glucan (17.4–19.3%) and xylan (2.8–2.9%). Whereas, the structural properties of OS lignin residues were characterized by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), thermogravimetric analysis and size exclusion chromatography (SEC). OS lignin residues displayed the main inter-unit linkages (β–β′ resinol (51.0–59.0%), followed by β-O-4′ alkyl aryl ethers (27.0–35.2%) and β-5′ phenylcoumaran (11.4–13.2%) substructures), high molecular weights (22,000–25900 Da), low S/G ratios (1.2–1.5) and phenolic groups content (48–55 mg GAE/g lignin). Moreover, OS lignin residues were dispersed in ELO to obtain thickened formulations, which were characterized by FTIR and NMR. Oil thickening was achieved by promoting the chemical crosslinking between lignocellulose hydroxyl groups and ELO epoxy groups, enabling the compatibilization of both components. Up to tenfold viscosity increment of the resulting thickened formulations in relation to ELO’s viscosity was observed. Besides, thickened formulations exhibited viscoelastic properties, evincing oil structuration to some extent.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work is collaborative research which is part of different projects: coordinated research projects (RTI2018-096080-B-C21 and RTI2018-096080-B-C22) and project PID2022-141965OB-C21 funded by MCIN/AEI/https://doi.org/10.13039/501100011033 and by “ERDF A way of making Europe”, TED 2021-132122B-C1 funded by MCIN/AEI/https://doi.org/10.13039/501100011033 and by the “European UnionNextGenerationEU/PRTR”, ENE2017-85819-C2-2-R funded by MINECO, and SUSTEC-CM S2018/EMT-4348 project funded by Comunidad de Madrid. The authors gratefully acknowledge the aforementioned financial support

Development of Bio-Based Materials: Synthesis, Characterization and Applications

The need to find suitable biomaterials and procedures from alternative products able to imitate or even enhance the performance of currently used products has become an important focus of research today due to the depletion of non-renewable resources and the increasing concern related to climate change, sustainability and environmental preservation [...

XIV International Congress of Control Electronics and Telecommunications: "Inclusive digital transformation for technological and social progress"

Contenido: Evaluación del efecto de una estimulación con campos eléctricos sobre el cartílago hialino. ; Clasificadores supervisados del cáncer de próstata. ; Desarrollo de un prototipo de colector solar lineal tipo Fresnel para la producción de vapor de agua. ; Estudio del comportamiento del panel fotovoltaico según la superficie instalada. ; Aprovechamiento aguas residuales y residuos del pacifico colombiano para generación eléctrica. ; Descripción de los Procesos Industriales Energéticamente Críticos en la Producción de Cacao en Santander. ; Reutilización energética de las vibraciones mecánicas en helicópteros. ; Navegación de robots móviles en formación de convoy. ; Emulador para desarrollo de proyectos iot y analíticas de datos. ; Bluelock una herramienta para prevenir ataques en bluetooth. ; Diseño e implementación de un gateway iot multiprotocolo. ; Caracterización de emulación de usuario primario en redes móviles de radio cognitiva. ; Metodología de diseño de antenas microstrip por caracterización del dieléctrico. ; Esquema de comunicación digital usando generador vectorial y SDR. ; Estrategia para coordinar y controlar los movimientos de un robot modular de tipo cadena basado en tecnología de internet de las cosas. ; Detección de información relevante en funciones de modo intrínseco. ; Evaluación del proceso de falla en mezclas asfálticas a partir del análisis digital de imágenes. ; Identificación y detección de fallas en un accionamiento utilizando NN-NARX. ; Navegación PRM en dron comercial y simulación GAZEBO. ; Control PID/Difuso de velocidad y torque de motores de motores. ; Invernadero automatizado, instrumentación y lógica difusa. ; Prototipo control de vehículo robot por señales EMG.Content: Evaluación del efecto de una estimulación con campos eléctricos sobre el cartílago hialino. ; Clasificadores supervisados del cáncer de próstata. ; Desarrollo de un prototipo de colector solar lineal tipo Fresnel para la producción de vapor de agua. ; Estudio del comportamiento del panel fotovoltaico según la superficie instalada. ; Aprovechamiento aguas residuales y residuos del pacifico colombiano para generación eléctrica. ; Descripción de los Procesos Industriales Energéticamente Críticos en la Producción de Cacao en Santander. ; Reutilización energética de las vibraciones mecánicas en helicópteros. ; Navegación de robots móviles en formación de convoy. ; Emulador para desarrollo de proyectos iot y analíticas de datos. ; Bluelock una herramienta para prevenir ataques en bluetooth. ; Diseño e implementación de un gateway iot multiprotocolo. ; Caracterización de emulación de usuario primario en redes móviles de radio cognitiva. ; Metodología de diseño de antenas microstrip por caracterización del dieléctrico. ; Esquema de comunicación digital usando generador vectorial y SDR. ; Estrategia para coordinar y controlar los movimientos de un robot modular de tipo cadena basado en tecnología de internet de las cosas. ; Detección de información relevante en funciones de modo intrínseco. ; Evaluación del proceso de falla en mezclas asfálticas a partir del análisis digital de imágenes. ; Identificación y detección de fallas en un accionamiento utilizando NN-NARX. ; Navegación PRM en dron comercial y simulación GAZEBO. ; Control PID/Difuso de velocidad y torque de motores de motores. ; Invernadero automatizado, instrumentación y lógica difusa. ; Prototipo control de vehículo robot por señales EMG