Development of environmentally friendly composite matrices from epoxidized cottonseed oil

The continuous rise in oil prices has led to the use of other ways to obtain polymer materials. This paper proposes a methodology to obtain a thermosetting resin from cottonseed oil by epoxidation process. The cottonseed oil contains as most representative fatty acids: 52.5% of linoleic acid (C18: 2), 23.9% of palmitic acid (C16: 0) and 17.6% of oleic acid (C18: 1); the real iodine index, which is indicative of the number of double bonds, has a value of 107. Epoxidized cottonseed oil (ECSO) has been successfully obtained using conventional epoxidation process with hydrogen peroxide, acetic acid and sulfuric acid, maintaining a constant temperature of 70 °C with homogeneous magnetic stirring. Average oxirane oxygen content (OOC) of 5.32% can be obtained by conventional epoxidation process which represents a yield over 83%. The epoxidized oil has been crosslinked with mixtures of two cyclic anhydrides to tailor different properties on final crosslinked thermosetting resins: on the one hand, methyl nadic anhydride (MNA) which is characterized by a rigid molecular structure and on the other hand, dodecenylsuccinic anhydride (DDSA) with a long side chain that can confer flexibility. The crosslinking process has been followed by dynamic differential scanning calorimetry (DSC), ionic mobility and oscillatory rheometry (OR) as well as gel time determination. The effect of the hardener mixture (wt.% DDSA:MNA) on mechanical performance of cured materials has been followed by flexural and impact tests as well as the evolution of the storage modulus (G′) by dynamic mechanical analysis (DMA) in torsion mode. By selecting the appropriate hardener mixture, it is possible to obtain crosslinked materials with different properties ranging from stiff matrices for ECSO crosslinked with MNA to flexible matrices for ECSO cured with DDSA. This has occurred with other thermosetting resins like epoxidized soy bean oil (ESBO) or epoxidized linseed oil (ELO). (C) 2014 Elsevier Ltd. All rights reserved.Authors thank Conselleria d'Educacio, Cultura i Esport (Generalitat Valenciana) Ref: GV/2014/008 for financial support.Carbonell Verdú, A.; Bernardi, L.; García García, D.; Sánchez Nacher, L.; Balart Gimeno, RA. (2015). Development of environmentally friendly composite matrices from epoxidized cottonseed oil. European Polymer Journal. 63:1-10. doi:10.1016/j.eurpolymj.2014.11.043S1106

Flipped classroom aplicado a prácticas de laboratorio de la asignatura “Ampliación de Ciencia de Materiales”

[ES] El cambio de metodología de enseñanza que se realizó en las prácticas de laboratorio de la asignatura “Ampliación de ciencia de materiales” fue con el propósito de sacar ventaja de las peculiaridades que presenta el grupo, es decir un número reducido de estudiantes y tiempo de dedicación tanto dentro de clase como fuera de ella, factores que permitieron un mejor control del proceso de enseñanza. El proceso de aprendizaje al que fue expuesto este grupo de estudiante retó la capacidad innata que tiene el ser humano al autoaprendizaje y a descubrir cómo superar sus puntos débiles, sacando el mayor provecho al tiempo disponible de estudio, es decir, asimilando la mayoría cantidad de información con una mínima inversión de tiempo. La evaluación realizada durante todo el proceso fue satisfactoria no solo para el estudiante reflejadas en las calificaciones obtenidas, sino también para el tutor que pudo observar cómo evolucionó el interés de los estudiantes al envolverse cada vez más en el contenido de las prácticas, siendo notable en las prácticas finales.[EN] The new teaching methodology carried out in the laboratory class of the subject “Ampliación de ciencia de materiales” was used to take advantage of the peculiarities of the student group, that is in fact, it is a reduced number of students and great dedication time both in-class and out-class, factors that allowed better overall control of the process. The learning process to which the group of students was exposed challenged the innate capacity of the human being to self learn and to discover how to overcome their weak points, making the most of the available study time, that is, assimilating most of the information in less time. The evaluation carried out throughout the process was satisfactory not only for the student showed in the grades obtained, but also for the teacher in charge who could observe how the interest of the students evolved as they became increasingly involved in the content of the practice, being remarkable in the final class.Lascano, D.; Sánchez-Nacher, L.; Fombuena, V.; Rojas-Lema, S.; Montañés, N. (2021). Flipped classroom aplicado a prácticas de laboratorio de la asignatura “Ampliación de Ciencia de Materiales”. En IN-RED 2020: VI Congreso de Innovación Educativa y Docencia en Red. Editorial Universitat Politècnica de València. 218-223. https://doi.org/10.4995/INRED2020.2020.11976OCS21822

Commissioning of the CALIFA Barrel Calorimeter of the R3^{3}B Experiment at FAIR

CALIFA is the high efficiency and energy resolution calorimeter for the R$^{3}$B experiment at FAIR, intended for detecting high energy charged particles and $\gamma$-rays in inverse kinematics direct reactions. It surrounds the reaction target in a segmented configuration of Barrel and Forward End-Cap pieces. The CALIFA Barrel consists of 1952 detection units made of CsI(Tl) long-shaped scintillator crystals, and it is being commissioned during the Phase0 experiments at FAIR. The first setup for the CALIFA Barrel commissioning is presented here. Results of detector performance with $\gamma$-rays are obtained, and show that the system fulfills the design requirements

The effect of maleinized linseed oil (MLO) on mechanical performance of poly(lactic acid)-thermoplastic starch (PLA-TPS) blends

[EN] In this work, poly(lactic acid), PLA and thermoplastic starch, TPS blends (with a fixed content of 30 wt.% TPS) were prepared by melt extrusion process to increase the low ductile properties of PLA. The TPS used contains an aliphatic/aromatic biodegradable polyester (AAPE) that provides good resistance to aging and moisture. This blend provides slightly improved ductile properties with an increase in elongation at break of 21.5% but phase separation is observed due to the lack of strong interactions between the two polymers. Small amounts of maleinized linseed oil (MLO) can positively contribute to improve the ductile properties of these blends by a combined plasticizing-compatibilizing effect. The elongation at break increases over 160% with the only addition of 6 phr MLO. One of the evidence of the plasticizing-compatibilizing effect provided by MLO is the change in the glass transition temperature (Tg) with a decrease of about 10 °C. Field emission scanning electron microscopy (FESEM) of PLA-TPS blends with varying amounts of maleinized linseed oil also suggests an increase in compatibility.This research was supported by the Ministry of Economy and Competitiveness-MINECO, Ref: MAT2014-59242-C2-1-R. Authors also thank to "Conselleria d'Educacio, Cultura i Esport"-Generalitat Valenciana, Ref: GV/2014/008 for financial support.Ferri Azor, JM.; García García, D.; Sánchez Nacher, L.; Fenollar Gimeno, OÁ.; Balart Gimeno, RA. (2016). The effect of maleinized linseed oil (MLO) on mechanical performance of poly(lactic acid)-thermoplastic starch (PLA-TPS) blends. Carbohydrate Polymers. 147:60-68. https://doi.org/10.1016/j.carbpol.2016.03.082S606814

Processing and characterization of high environmental efficiency composites based on PLA and hazelnut shell flour (HSF) with biobased plasticizers derived from epoxidized linseed oil (ELO)

[EN] Different amounts of epoxidized linseed oil (ELO) have been added to poly(lactic acid)-PLA composites with hazelnut shell flour (HSF) to provide a plasticizing effect and improve the low intrinsic ductile properties of PLA/HSF composites. Mechanical, thermal, thermo-mechanical and dynamic mechanical properties have been studied in terms of the weight percentage ELO. Mechanical resistant properties in both tensile and flexural tests decrease with wt.% ELO while a remarkable increase with wt.% ELO is obtained. These results reveal a clear plasticization effect of ELO but, in addition, internal structure of PLA/HSF/ELO composites shows good PLA-HSF (matrix-particle) interactions so that indicating that ELO also provides a coupling effect between PLA matrix and HSF filler. ELO addition leads to a decrease in storage modulus (G ) obtained by dynamic mechanical thermal analysis (DMTA) in torsion mode thus giving clear evidence of the plasticization effect of ELO. Overall, the use of ELO in PLA/HSF composites is an attracting way to improve the low intrinsic fragility of these green composites; furthermore, ELO provides an improvement on thermal stability and a coupling effect between the polymer matrix and the surrounding lignocellulosic filler.This research was supported by the Ministry of Economy and Competitiveness - MINECO, Grant Number: MAT2014-59242-C2-1-R. Authors also thank to "Conselleria d'Educacio, Cultura i Esport" - Generalitat Valenciana, Grant Number: GV/2014/008 for financial support.Balart Gimeno, JF.; Fombuena Borrás, V.; Fenollar Gimeno, OÁ.; Boronat Vitoria, T.; Sánchez Nacher, L. (2016). Processing and characterization of high environmental efficiency composites based on PLA and hazelnut shell flour (HSF) with biobased plasticizers derived from epoxidized linseed oil (ELO). Composites Part B: Engineering. 86:168-177. https://doi.org/10.1016/j.compositesb.2015.09.063S1681778

A longitudinal study of gene expression in first-episode schizophrenia; exploring relapse mechanisms by co-expression analysis in peripheral blood

Little is known about the pathophysiological mechanisms of relapse in first-episode schizophrenia, which limits the study of potential biomarkers. To explore relapse mechanisms and identify potential biomarkers for relapse prediction, we analyzed gene expression in peripheral blood in a cohort of first-episode schizophrenia patients with less than 5 years of evolution who had been evaluated over a 3-year follow-up period. A total of 91 participants of the 2EPs project formed the sample for baseline gene expression analysis. Of these, 67 provided biological samples at follow-up (36 after 3 years and 31 at relapse). Gene expression was assessed using the Clariom S Human Array. Weighted gene co-expression network analysis was applied to identify modules of co-expressed genes and to analyze their preservation after 3 years of follow-up or at relapse. Among the 25 modules identified, one module was semi-conserved at relapse (DarkTurquoise) and was enriched with risk genes for schizophrenia, showing a dysregulation of the TCF4 gene network in the module. Two modules were semi-conserved both at relapse and after 3 years of follow-up (DarkRed and DarkGrey) and were found to be biologically associated with protein modification and protein location processes. Higher expression of DarkRed genes was associated with higher risk of suffering a relapse and early appearance of relapse (p = 0.045). Our findings suggest that a dysregulation of the TCF4 network could be an important step in the biological process that leads to relapse and suggest that genes related to the ubiquitin proteosome system could be potential biomarkers of relapse. © 2021, The Author(s)

The relationship between genetic liability, childhood maltreatment, and IQ: findings from the EU-GEI multicentric case–control study

This study investigated if the association between childhood maltreatment and cognition among psychosis patients and community controls was partially accounted for by genetic liability for psychosis. Patients with first-episode psychosis (N = 755) and unaffected controls (N = 1219) from the EU-GEI study were assessed for childhood maltreatment, intelligence quotient (IQ), family history of psychosis (FH), and polygenic risk score for schizophrenia (SZ-PRS). Controlling for FH and SZ-PRS did not attenuate the association between childhood maltreatment and IQ in cases or controls. Findings suggest that these expressions of genetic liability cannot account for the lower levels of cognition found among adults maltreated in childhood

Viscoelastic models in green composites from PLA and hazelnut shell fillers with a natural plasticizer from epoxidized linseed oil

In a same way to polymeric materials, some composite materials as it is the case of green composites, are characterized by a viscoelastic behaviour which plays a key role in their mechanical properties with time. The use of some engineering materials could be restricted as their mechanical properties could be highly affected by temperature or time. For this reason, this work is focused on the modeling of the viscoelastic behaviour of this biomaterial composite with a biobased polymer matrix from poly(lactic acid) and a lignocellulosic reinforcement/filler coming from hazelnut shell with different plasticizer content. In particular, a biobased plasticizer, namely epoxidized linseed oil (ELO) has been employed. A first approach to the viscoelastic behaviour of these composites is summarized in this work. The Maxwell model considers a series combination of the elastic reponse (represented by a spring) and the viscous contribution (represented by a dashpot). The Kelvin-Voigt model considers the same physical elements (spring and dashpot) but coupled in parallel. As these two basic visceolastic models show important restrictions regarding the real viscoelastic behaviour, this work also considers a series combination of the Maxwell model and the Kelvin-Voigt model, known as Burgers model. This works focuses on determining the different parameters of the Burgers model to fit experimental data from PLA-hazelnut shell flour biocomposites with varying plasticizer (ELO) content

Optimization of thermoplastic matrix composite materials of renewable origin with pine fiber reinforcement

In recent years, there has been a significant increase in social awareness of environmental problems related to high waste generation, oil scarcity and the growing need to reduce the carbon footprint. In this context, polymers from renewable sources can successfully reduce the use of fossil resources. This research work presents the study of polymer matrix composites from high density polyethylene of renewable origin (bioHPDE) and fibers extracted from the strobili of the common pine (Pinus halepensis) typical of the Mediterranean area, characterized by its high percentage of cellulose, and for being very abundant in the natural and economic environment. The research has focused on the influence of a compatibilizing agent based on polyethylene grafted with maleic anhydride on the final performance of the composite material. The resulting composites have been processed by extrusion and subsequent injection molding and a characterization focused on mechanical and thermal properties has been carried out. The results have demonstrated the optimization of the performance of the composite by using the compatibilizer, offering a significant improvement of the fiber-matrix interaction and thus validating its use in this type of composites. The result is a wood plastic composite (WPC) with a wide range of properties depending on the filler content used, providing a highly versatile material with applications in various industrial sectors

Properties of Biobased Epoxy Resins from Epoxidized Soybean Oil (ESBO) Cured with Maleic Anhydride (MA)

[EN] Epoxidized soybean oil (ESBO), obtained from a renewable resource was used in the production of thermoset resins. Samples of the ESBO were initially treated with maleic anhydride, equal mixture of catalyst (1,3-butanediol anhydrous and benzyldimethylamine) and the mixture was cured for 5 h at different temperatures. After the curing process, the ratio between the ESBO and the anhydride (ratio EEW:AEW) was evaluated in terms of the different mechanical properties produced using flexural, Shore D hardness and Charpy impact tests. The sample with the best mechanical properties was that with an EEW:AEW ratio of 1:1.0 which leads to best balanced behavior and this could be representative for the maximum crosslinking degree. Also, thermal characteristics were evaluated during the crosslinking process using differential scanning calorimetry, In addition, other thermal characteristics of the cured materials were obtained by determining the heat deflection temperature and the Vicat softening temperature. The coefficient of thermal expansion was determined using thermo-mechanical analysis. In accordance with the mechanical behavior, the best thermal properties were obtained for samples with an EEW:AEW ratio of 1:1.0. As a result of this work, a biologically based epoxy resin with good mechanical properties and flexibility was obtained. © AOCS 2012.This research is part of the IPT-310000-2010-037, "ECOTEXCOMP: research and development of textile structures applicable as reinforcement in compound materials of an ecological nature" project, financed by the Ministry of Science and Innovation, with a grant of 189,540.20 EUR, as part of the National Scientific Research, Development and Technological Innovation 2008-2011 plan, co-financed by the European Union through FEDER, Technology fund 2007-2013, Operative Program of R and D to benefit companies. J. M. Espana gives thanks to the Polytechnic University of Valencia (UPV) for their financial support through an FPI-UPV grant.España Giner, JM.; Sánchez Nacher, L.; Boronat Vitoria, T.; Fombuena Borrás, V.; Balart Gimeno, RA. (2012). Properties of Biobased Epoxy Resins from Epoxidized Soybean Oil (ESBO) Cured with Maleic Anhydride (MA). 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