32 research outputs found

    Evaluation of Styrene Content over Physical and Chemical Properties of Elastomer/TPS-EVOH/Chicken Feather Composites

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    A series of styrene-butadiene (SB) elastomer/thermoplastic starch (TPS)/ethylene vinyl alcohol copolymer (EVOH) composites were modified including chicken feathers in its formulation, which have the main component keratin. The composites were prepared by means of melt blending, and their chemical interactions were evaluated by means of infrared spectroscopy (FTIR), and their thermal properties as Tg values were investigated using differential scanning calorimetry (DSC), thermal stability using thermogravimetric analysis (TGA), and viscoelastic properties with dynamic mechanical analysis (DMA). The styrene content in SB was changed in 3 levels, and chicken feather content also changed in 3 levels. It was identified that Tg value in composites decreases that is attributed to the styrene content in elastomer and that the chicken feather improved the storage modulus of composite. The thermal stability of composites also was affected by the presence of chicken feathers due its good thermal properties

    Evaluation of Addition of Reactive Resin for an Adhesive Formulation of Pressure-Sensitive Adhesive

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    Nowadays, adhesive industry is growing, and its development will be important in a short future because it offers good returns, and in some cases it is a better option for packaging and sealing with advantages in prices, productivity and weight reduction. In terms of joining and/or sealing, adhesives are well positioned among joining systems; however, knowledge about adhesives is need for their efficient use and only through proper design of the union can be achieved satisfactory results. In this chapter, a development of a formulation of pressure-sensitive adhesive based on styrene-butadiene copolymers using a reactive resin is reported. Non-aromatic solvents were used in adhesive formulation with the aim of avoiding the emission of harmful solvents into the Atmosphere, and the adequate combination and amount of solvents were found. The effect of addition of a phenolic resin in the adhesive formulation as a crosslinking agent was evaluated. By means Fourier Transform Infrared spectroscopy (FTIR), the crosslinking reaction was also studied. The performance of adhesive formulation was evaluated by means of dynamic mechanical analysis (DMA)

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

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    The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

    Study of the dispersion of Cloisite 10A in recycled polyethylene terephtalate by extrusion

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    This research focuses on clay dispersion of commercial Cloisite 10A in recycled PET (RPET) to improve the properties of recycled polymer lost in the reprocessing of materials, specifically during extrusion. Varying mixtures of RPET/Cloisite 10A were prepared in a single screw extruder. The mixtures obtained were reprocessed in capillary rheometer-type single screw extruder and passed through a capillary die, at high shear stress to increase the dispersion of clay in the polymer matrix. Results show physical degradation of materials. X-ray diffraction (XRD) indicated exfoliation of clay with low concentrations. Furthermore, rheology results show that viscosity rate decreases with increase in clay concentration in the mixtures. Scanning electron microscopy (SEM) reveals low dispersion of clay with an increase of concentration

    Study of the dispersion of Cloisite 10A in recycled polyethylene terephtalate by extrusion

    No full text
    This research focuses on clay dispersion of commercial Cloisite10A in recycled PET (RPET) to improve the properties of recycled polymer lost in the reprocessing of materials, specifically during extrusion. Varying mixtures of RPET/Cloisite 10A were prepared in a single screw extruder. The mixtures obtained were reprocessed in capillary rheometer-type single screw extruder and passed through a capillary die, at high shear stress to increase the dispersion of clay in the polymer matrix. Results show physical degradation of materials. X-ray diffraction(XRD) indicated exfoliation of clay with low concentrations. Furthermore, rheology results show that viscosity rate decreases with increase in clay concentration in the mixtures. Scanning electron microscopy (SEM) reveals low dispersion of clay with an increase of concentration.Esta investigación fue enfocada en la dispersión de una arcilla de marca comercial Cloisite 10A en PET reciclado (RPET) para mejorar las propiedades del polímero reciclado que se perdieron en el reprocesamiento de los materiales, específicamente durante la extrusión. Diferentes mezclas de RPET/Cloisite 10A fueron preparadas en un extrusor monohusillo. Las mezclas obtenidas fueron reprocesadas en un extrusor monohusillo tipo reómetro y pasadas a traves de un dado capilar en altos esfuerzos de corte para paraincrementar la dispersión de la arcilla en la matriz polimérica. Los resultados muestran degradación física de los materiales. Difracción de rayos X (XRD) indica exfoliación de la arcilla con bajas concentraciones. Además, los resultados reológicos muestran decremento en la viscosidad con incremento de la concentración de la arcilla en las mezclas. Microscopia electrónica de barrido (SEM) revela baja dispersión de la arcilla con incremento de la concentración

    Study of the dispersion of Cloisite 10A in recycled polyethylene terephtalate by extrusion

    Get PDF
    This research focuses on clay dispersion of commercial Cloisite 10A in recycled PET (RPET) to improve the properties of recycled polymer lost in the reprocessing of materials, specifically during extrusion. Varying mixtures of RPET/Cloisite 10A were prepared in a single screw extruder. The mixtures obtained were reprocessed in capillary rheometer-type single screw extruder and passed through a capillary die, at high shear stress to increase the dispersion of clay in the polymer matrix. Results show physical degradation of materials. X-ray diffraction (XRD) indicated exfoliation of clay with low concentrations. Furthermore, rheology results show that viscosity rate decreases with increase in clay concentration in the mixtures. Scanning electron microscopy (SEM) reveals low dispersion of clay with an increase of concentration.Esta investigación fue enfocada en la dispersión de una arcilla de marca comercial Cloisite 10A en PET reciclado (RPET) para mejorar las propiedades del polímero reciclado que se perdieron en el reprocesamiento de los materiales, específicamente durante la extrusión. Diferentes mezclas de RPET/Cloisite 10A fueron preparadas en un extrusor monohusillo. Las mezclas obtenidas fueron reprocesadas en un extrusor monohusillo tipo reómetro y pasadas a traves de un dado capilar en altos esfuerzos de corte para para incrementar la dispersión de la arcilla en la matriz polimérica. Los resultados muestran degradación física de los materiales. Difracción de rayos X (XRD) indica exfoliación de la arcilla con bajas concentraciones. Además, los resultados reológicos muestran decremento en la viscosidad con incremento de la concentración de la arcilla en las mezclas. Microscopia electrónica de barrido (SEM) revela baja dispersión de la arcilla con incremento de la concentración
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