cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6968135
title: Effects of Rotor Speed on Peroxide/Bismaleimide Cured Polypropylene/Nitrile Rubber Thermoplastic Vulcanizates (TPVs)

description: Elastomer thermoplastics are a class of polymeric materials that received industry attention due to the possibility of joining the elastic of elastomers with the thermoplastics processability. The synergistic properties are linked to the appropriate processing. This study evaluated the effect of rotor speed during polymer mixing and the dynamic vulcanization process of polypropylene and nitrile rubber blends. Bismaleimide was employed as multipurpose agent (crosslinking coagent for peroxide and compatibilizer). Morphology, mechanical properties, compression set and oil resistance tests were evaluated for compositions containing 50 and 70 PHR of elastomer. The compatibilization of TPV was realized by infrared spectroscopy. It was shown a compatibilizer effect and better dispersion, achieving the inversion phase, only studying the effect of processing conditions (rotor speed, addition sequence, additives), without any extra interfacial agent. There is a tendency to obtain better performance with decrease speed at dynamic vulcanization or/and at torque stabilization, mainly for blends with 50 PHR of rubber.
DOI: 10.6084/m9.figshare.6968135.v1
title: Effects of Rotor Speed on Peroxide/Bismaleimide Cured Polypropylene/Nitrile Rubber Thermoplastic Vulcanizates (TPVs)

description: Elastomer thermoplastics are a class of polymeric materials that received industry attention due to the possibility of joining the elastic of elastomers with the thermoplastics processability. The synergistic properties are linked to the appropriate processing. This study evaluated the effect of rotor speed during polymer mixing and the dynamic vulcanization process of polypropylene and nitrile rubber blends. Bismaleimide was employed as multipurpose agent (crosslinking coagent for peroxide and compatibilizer). Morphology, mechanical properties, compression set and oil resistance tests were evaluated for compositions containing 50 and 70 PHR of elastomer. The compatibilization of TPV was realized by infrared spectroscopy. It was shown a compatibilizer effect and better dispersion, achieving the inversion phase, only studying the effect of processing conditions (rotor speed, addition sequence, additives), without any extra interfacial agent. There is a tendency to obtain better performance with decrease speed at dynamic vulcanization or/and at torque stabilization, mainly for blends with 50 PHR of rubber.
DOI: 10.6084/m9.figshare.6992537
title: High Temperature Tensile and Strain Hardening Behaviour of AA5052/9 vol. %ZrB2 insitu Composite

description: Various mechanical components such as piston, cylinder blocks, brakes and drums, have to operate under high temperature condition during their service life. Therefore, to meet the demand of high strength materials, a detailed analysis of their synthesis and high temperature tensile behaviour is of utmost importance. Present study is an effort in this direction to develop AA5052/9vol. %ZrB2 insitu composite by salt-metal reaction technique. An insitu reaction between molten aluminium alloy and two inorganic salts K2ZrF6 and KBF4 begins at 860°C and continues up to 30 min. The resulting reaction product ZrB2 is desired reinforcement confirmed by XRD analysis. Microstructural study was performed to analyse grain size, particle morphology, and their distribution in the matrix. Tensile tests were conducted at temperatures ranging from room temperature (RT) to 200°C with an interval of 50ºC. The results revealed the decreasing trend of UTS and YS (0.2% off set) with increase in temperature; however ductility increased with temperature. The composite is able to maintain about 81% of its ambient temperature strength at 150°C and 72% at 200°C. Strain hardening exponent was not significantly affected with temperature and tensile properties were correlated with fractured surface morphology examined under SEM to understand the mechanism.
DOI: 10.6084/m9.figshare.6992537.v1
title: High Temperature Tensile and Strain Hardening Behaviour of AA5052/9 vol. %ZrB2 insitu Composite

description: Various mechanical components such as piston, cylinder blocks, brakes and drums, have to operate under high temperature condition during their service life. Therefore, to meet the demand of high strength materials, a detailed analysis of their synthesis and high temperature tensile behaviour is of utmost importance. Present study is an effort in this direction to develop AA5052/9vol. %ZrB2 insitu composite by salt-metal reaction technique. An insitu reaction between molten aluminium alloy and two inorganic salts K2ZrF6 and KBF4 begins at 860°C and continues up to 30 min. The resulting reaction product ZrB2 is desired reinforcement confirmed by XRD analysis. Microstructural study was performed to analyse grain size, particle morphology, and their distribution in the matrix. Tensile tests were conducted at temperatures ranging from room temperature (RT) to 200°C with an interval of 50ºC. The results revealed the decreasing trend of UTS and YS (0.2% off set) with increase in temperature; however ductility increased with temperature. The composite is able to maintain about 81% of its ambient temperature strength at 150°C and 72% at 200°C. Strain hardening exponent was not significantly affected with temperature and tensile properties were correlated with fractured surface morphology examined under SEM to understand the mechanism.
DOI: 10.6084/m9.figshare.6992540
title: Multifractal Analysis of Particle Dispersion and Interphase Percolation in Nanocomposites

description: The dispersion of nanoparticles in nanocomposites of an epoxy matrix reinforced with alumina (10nm) and zinc oxide (100nm) is analyzed using FIB/FESEM images, varying the volumetric fraction of fillers from 0.2 % to 6.0 %. The nanofillers dispersion images were transformed to binary files and the multifractal spectrum was calculated. From these data the relation between agglomerate and individual particle dimensionalities related to the interphase percolation was investigated. Interphase percolation of nanocomposites should be achieved when the dimensionality of agglomerations is greater than the dimensionality of individual particles. The actual percolation state of the interphase is determined, matching the experimental nanocomposites behavior for electrical behavior at AC and dielectric breakdown at DC.
DOI: 10.6084/m9.figshare.6992540.v1
title: Multifractal Analysis of Particle Dispersion and Interphase Percolation in Nanocomposites

description: The dispersion of nanoparticles in nanocomposites of an epoxy matrix reinforced with alumina (10nm) and zinc oxide (100nm) is analyzed using FIB/FESEM images, varying the volumetric fraction of fillers from 0.2 % to 6.0 %. The nanofillers dispersion images were transformed to binary files and the multifractal spectrum was calculated. From these data the relation between agglomerate and individual particle dimensionalities related to the interphase percolation was investigated. Interphase percolation of nanocomposites should be achieved when the dimensionality of agglomerations is greater than the dimensionality of individual particles. The actual percolation state of the interphase is determined, matching the experimental nanocomposites behavior for electrical behavior at AC and dielectric breakdown at DC.
DOI: 10.6084/m9.figshare.6992534.v1
title: Response to Ballistic Impact of Alumina-UHMWPE Composites

description: The response to ballistic impact of alumina-ultra high molecular weight polyethylene (UHMWPE) composites with different relative concentrations of alumina was investigated. The impact tests were carried out at subsonic speed using a compressed air system. The results showed that the depth of penetration (DOP) in a Medium Density Fiberboard (MDF) bulkhead protected by a disk of the composite decreased with increasing concentration of alumina in the composite. Scanning electron microscopy (SEM) images of composites with 80 %, 85 % and 95 % alumina showed transgranular, intergranular and ductile fracture mechanisms.
DOI: 10.6084/m9.figshare.6992534
title: Response to Ballistic Impact of Alumina-UHMWPE Composites

description: The response to ballistic impact of alumina-ultra high molecular weight polyethylene (UHMWPE) composites with different relative concentrations of alumina was investigated. The impact tests were carried out at subsonic speed using a compressed air system. The results showed that the depth of penetration (DOP) in a Medium Density Fiberboard (MDF) bulkhead protected by a disk of the composite decreased with increasing concentration of alumina in the composite. Scanning electron microscopy (SEM) images of composites with 80 %, 85 % and 95 % alumina showed transgranular, intergranular and ductile fracture mechanisms.
DOI: 10.6084/m9.figshare.6991520
title: Effect of LLDPE on Aging Resistance and Thermal, Mechanical, Morphological Properties of UHMWPE/LLDPE Blends

description: Blends of ultra-high molecular weight polyethylene (UHMWPE) and different contents (0, 10, 20 and 30 wt%) of linear low-density polyethylene (LLDPE) with and without maleic anhydride-grafted LLDPE (LLDPE-g-MA) were prepared by melt blending and aging resistance, thermal and mechanical properties were evaluated. The degree of crystallinity increases with the content of LLDPE in the blends. On the other hand, the addition of compatibilizer agent modifies the crystallinity and the crystallite size. Non-compatibilized blends have excellent impact resistance properties and the addition of LLDPE-g-MA aids processing but decrease the impact resistance of the blends. Thermal and mechanical properties were greatly affected by thermal and water aging. The thermal aging leads to an increase in the degree of crystallinity and consequent a decrease in impact resistance.
DOI: 10.6084/m9.figshare.6991520.v1
title: Effect of LLDPE on Aging Resistance and Thermal, Mechanical, Morphological Properties of UHMWPE/LLDPE Blends

description: Blends of ultra-high molecular weight polyethylene (UHMWPE) and different contents (0, 10, 20 and 30 wt%) of linear low-density polyethylene (LLDPE) with and without maleic anhydride-grafted LLDPE (LLDPE-g-MA) were prepared by melt blending and aging resistance, thermal and mechanical properties were evaluated. The degree of crystallinity increases with the content of LLDPE in the blends. On the other hand, the addition of compatibilizer agent modifies the crystallinity and the crystallite size. Non-compatibilized blends have excellent impact resistance properties and the addition of LLDPE-g-MA aids processing but decrease the impact resistance of the blends. Thermal and mechanical properties were greatly affected by thermal and water aging. The thermal aging leads to an increase in the degree of crystallinity and consequent a decrease in impact resistance.
DOI: 10.6084/m9.figshare.7075655
title: Novel Drying Process Assisted by Microwave to Iron Ore Pelletizing

description: Drying has became critical to iron ore pellet production, due to increasing inability to withdrawal moisture from the green pellets, especially faced by goethitic iron ore producers. Most of the existing pelletizing furnaces do not support increase heating rates nor changes in furnaces length, without compromise pellet quality. The present study evaluates an innovative alternative for the actual fully convective drying process composed by an up-draught drying (UDD) and down-draught drying stage (DDD), through the application of microwave energy to assist the existing process. In the present work, the process was simulated in a pot grate where industrial parameters can be simulated. The microwave generator (power input of 10 MW and 915 MHz) was connected in a traditional static pot grate at the hood by a microwave conductor. The experiments show elimination of the over-wet zone at the upper layer of pellet observed at the traditional process. A reduction greater than 7% of the moisture in UDD was achieved, while the convective process adds extra moist to the green pellets modifying the pellet shape.
DOI: 10.6084/m9.figshare.7075655.v1
title: Novel Drying Process Assisted by Microwave to Iron Ore Pelletizing

description: Drying has became critical to iron ore pellet production, due to increasing inability to withdrawal moisture from the green pellets, especially faced by goethitic iron ore producers. Most of the existing pelletizing furnaces do not support increase heating rates nor changes in furnaces length, without compromise pellet quality. The present study evaluates an innovative alternative for the actual fully convective drying process composed by an up-draught drying (UDD) and down-draught drying stage (DDD), through the application of microwave energy to assist the existing process. In the present work, the process was simulated in a pot grate where industrial parameters can be simulated. The microwave generator (power input of 10 MW and 915 MHz) was connected in a traditional static pot grate at the hood by a microwave conductor. The experiments show elimination of the over-wet zone at the upper layer of pellet observed at the traditional process. A reduction greater than 7% of the moisture in UDD was achieved, while the convective process adds extra moist to the green pellets modifying the pellet shape.
DOI: 10.6084/m9.figshare.7020530
title: Nonisothermal Melt Crystallization Kinetics of PHB/babassu Compounds

description: PHB has interesting features such as biodegradability, sustainability and durability. However, it has a high cost, in addition to being hard, brittle and thermally unstable during processing. Therefore, it was found convenient to study the crystallization of PHB/20% babassu compounds, with the intention of reducing the cost of the composite, in addition to seeking improvements in thermal properties. In this work, the parameters of melt crystallization were studied for PHB/20% babassu compounds driven at different cooling rates under a nitrogen flow. Subsequently, crystallization parameters were compared for different cooling rates. A kinetic analysis of data obtained for melt crystallization was performed. Among the models studied, Pseudo-Avrami showed the best correlation with experimental data, with discrepancy between +6% and -4%. The Mo model presented a discrepancy between +15% and -8%. A modified Mo model discrepancies are reduced to +3% and -4% within the range of validity of the model.
DOI: 10.6084/m9.figshare.7020530.v1
title: Nonisothermal Melt Crystallization Kinetics of PHB/babassu Compounds

description: PHB has interesting features such as biodegradability, sustainability and durability. However, it has a high cost, in addition to being hard, brittle and thermally unstable during processing. Therefore, it was found convenient to study the crystallization of PHB/20% babassu compounds, with the intention of reducing the cost of the composite, in addition to seeking improvements in thermal properties. In this work, the parameters of melt crystallization were studied for PHB/20% babassu compounds driven at different cooling rates under a nitrogen flow. Subsequently, crystallization parameters were compared for different cooling rates. A kinetic analysis of data obtained for melt crystallization was performed. Among the models studied, Pseudo-Avrami showed the best correlation with experimental data, with discrepancy between +6% and -4%. The Mo model presented a discrepancy between +15% and -8%. A modified Mo model discrepancies are reduced to +3% and -4% within the range of validity of the model.
DOI: 10.6084/m9.figshare.20020746
title: F-127-Assisted Sol-Gel Synthesis of Gd2O3:Eu3+ Powders and Films

description: In the current work, the influence of Pluronic F-127 (S = F-127) and temperature on the luminescent properties of Gd2O3:Eu3+ (Gd:S = 1:2) powders and films was studied. In order to synthesize the powders and films (by the dip-coating technique), Gd2O3: Eu3+ (5 mol%) ceramics were elaborated by the sol-gel route, using gadolinium and europium nitrates as precursors. The results obtained by means of X-ray diffraction, confirmed the presence of the cubic structure of Gd2O3 (in 800 ºC heat-treated powders and 700 ºC heat-treated films), and crystals with nanometer sizes of ~19 nm, and ~15 nm, corresponding to the spherical and laminar-like morphologies of densified powders and films, respectively. Crystallites from the cubic and monoclinic structure were present on Gd2O3: Eu3+-modified films up to 800 ºC. Chemical identification of the bonds present in the films was performed by Fourier transform infrared spectroscopy, which identified representative infrared absorption at 543 cm-1, attributable to the Gd-O vibration. Photoluminescence studies showed that when the powders and films were heat-treated at 800 ºC, the intensity of their luminescence at the 5D0→7F2 Eu3+ transition (618 nm) was enhanced by the presence of F-127.
DOI: 10.6084/m9.figshare.20020746.v1
title: F-127-Assisted Sol-Gel Synthesis of Gd2O3:Eu3+ Powders and Films

description: In the current work, the influence of Pluronic F-127 (S = F-127) and temperature on the luminescent properties of Gd2O3:Eu3+ (Gd:S = 1:2) powders and films was studied. In order to synthesize the powders and films (by the dip-coating technique), Gd2O3: Eu3+ (5 mol%) ceramics were elaborated by the sol-gel route, using gadolinium and europium nitrates as precursors. The results obtained by means of X-ray diffraction, confirmed the presence of the cubic structure of Gd2O3 (in 800 ºC heat-treated powders and 700 ºC heat-treated films), and crystals with nanometer sizes of ~19 nm, and ~15 nm, corresponding to the spherical and laminar-like morphologies of densified powders and films, respectively. Crystallites from the cubic and monoclinic structure were present on Gd2O3: Eu3+-modified films up to 800 ºC. Chemical identification of the bonds present in the films was performed by Fourier transform infrared spectroscopy, which identified representative infrared absorption at 543 cm-1, attributable to the Gd-O vibration. Photoluminescence studies showed that when the powders and films were heat-treated at 800 ºC, the intensity of their luminescence at the 5D0→7F2 Eu3+ transition (618 nm) was enhanced by the presence of F-127.
DOI: 10.6084/m9.figshare.7974239
title: Intrinsic Orientation of Hydroxyapatite Grains on the Surface of Dense Pellets Produced by Uniaxial Pressing

description: Bioceramics synthesized in laboratories must undergo biological tests that consider the final format and all the processing steps involved in the production of the final device. However, in many cases, the synthesized materials are characterized in formats very different from those that will ultimately be implanted into the body. Once living cells are directly cultured on surfaces, a mismatch between bulk and surface microstructural characterizations often leads to the misinterpretation of biological responses. Therefore, our objective in this work was to determine whether and at what level significant microstructural changes can occur between the surface and the bulk of hydroxyapatite pellets produced by uniaxial pressing followed by calcination. Our results showed that the as-synthesized hydroxyapatite crystals had a preferential orientation along the [0 0 1] direction. The calcination process followed by grain growth inhibited this texture feature. However, on the pellet surfaces, the initial orientation was preserved. At the same time, crystallite growth was inhibited, and the cell unit volume of the crystals on the surface was significantly lower than that of the crystals in the bulk. These results demonstrated that the crystallographic features on the surface of hydroxyapatite pellets can be completely different from those observed for the bulk.
DOI: 10.6084/m9.figshare.7974239.v1
title: Intrinsic Orientation of Hydroxyapatite Grains on the Surface of Dense Pellets Produced by Uniaxial Pressing

description: Bioceramics synthesized in laboratories must undergo biological tests that consider the final format and all the processing steps involved in the production of the final device. However, in many cases, the synthesized materials are characterized in formats very different from those that will ultimately be implanted into the body. Once living cells are directly cultured on surfaces, a mismatch between bulk and surface microstructural characterizations often leads to the misinterpretation of biological responses. Therefore, our objective in this work was to determine whether and at what level significant microstructural changes can occur between the surface and the bulk of hydroxyapatite pellets produced by uniaxial pressing followed by calcination. Our results showed that the as-synthesized hydroxyapatite crystals had a preferential orientation along the [0 0 1] direction. The calcination process followed by grain growth inhibited this texture feature. However, on the pellet surfaces, the initial orientation was preserved. At the same time, crystallite growth was inhibited, and the cell unit volume of the crystals on the surface was significantly lower than that of the crystals in the bulk. These results demonstrated that the crystallographic features on the surface of hydroxyapatite pellets can be completely different from those observed for the bulk.
DOI: 10.6084/m9.figshare.7974842
title: Influence of CaO Addition, FeO/SiO2 , and MgO/SiO2 on the Melting Characteristic Temperatures of FeO-SiO2-MgO-CaO System

description: In order to decrease the oxidation temperature of fayalite in molten nickel slags, the influence of CaO addition, FeO/SiO2, and MgO/SiO2 on melting characteristic temperatures of FeO-SiO2-MgO-CaO system were investigated. The melting characteristic temperatures, including softening temperature (Ts), hemispherical temperature (Th), and flow temperature (Tf),were measured with hot stage microscope. Experimental results showed that the melting characteristic temperatures first decreased sharply and then increased slowly with increasing w(CaO) for samples at given FeO/SiO2 and MgO/SiO2 ratios. The melting characteristic temperatures of samples without CaO addition were much higher than that of samples with different CaO addition, which was mainly caused by the phase components at different compositions. The variation of melting characteristic temperatures were described in detail. Phase components and liquid fractions were calculated by FactSage 7.1, which was good agreement with the XRD patterns.
DOI: 10.6084/m9.figshare.7974842.v1
title: Influence of CaO Addition, FeO/SiO2 , and MgO/SiO2 on the Melting Characteristic Temperatures of FeO-SiO2-MgO-CaO System

description: In order to decrease the oxidation temperature of fayalite in molten nickel slags, the influence of CaO addition, FeO/SiO2, and MgO/SiO2 on melting characteristic temperatures of FeO-SiO2-MgO-CaO system were investigated. The melting characteristic temperatures, including softening temperature (Ts), hemispherical temperature (Th), and flow temperature (Tf),were measured with hot stage microscope. Experimental results showed that the melting characteristic temperatures first decreased sharply and then increased slowly with increasing w(CaO) for samples at given FeO/SiO2 and MgO/SiO2 ratios. The melting characteristic temperatures of samples without CaO addition were much higher than that of samples with different CaO addition, which was mainly caused by the phase components at different compositions. The variation of melting characteristic temperatures were described in detail. Phase components and liquid fractions were calculated by FactSage 7.1, which was good agreement with the XRD patterns.