Pub Date : 2023-05-08DOI: 10.1590/1980-5373-mr-2022-0469
D. Trejo-Zamudio, M. Morales-Luna, R. Aruna-Devi, C. E. Pérez-García, A. Sosa-Domínguez, J. Quiñones-Galván, F. Moure-Flores, J. Santos-Cruz
,
{"title":"Optoelectronic Properties of CuSbS2 and Cu12Sb4S13 Thin Films for Thermoelectric Applications","authors":"D. Trejo-Zamudio, M. Morales-Luna, R. Aruna-Devi, C. E. Pérez-García, A. Sosa-Domínguez, J. Quiñones-Galván, F. Moure-Flores, J. Santos-Cruz","doi":"10.1590/1980-5373-mr-2022-0469","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0469","url":null,"abstract":",","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67303072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1590/1980-5373-mr-2022-0357
F. Okamoto, Mara Cristina Lopes Oliveira, Adenilson Almeida Silva, R. Droppa Jr, R. A. Antunes
In the present work, the AZ61 alloy, one of the most important commercial structural magnesium alloys, was anodized in three different alkaline electrolytes consisting of 3 M KOH + 0.15 M Na 2 SiO 3 + 0.1 M Na 2 B 4 O 7 .10H 2 O, 3 M KOH + 0.5 M Na 3 PO 4 and 3 M KOH + 0.50 M Na 2 SiO 3 . The treatment was conducted at two different current densities, 20 and 30 mA.cm -2 for 10 minutes. The anodized layers were characterized by scanning electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy. The corrosion resistance was assessed by potentiodynamic polarization tests. The SCC behavior was studied using slow strain rate tests in 0.1 M NaCl solution at room temperature. Conventional tensile tests were also conducted in air. The susceptibility to SCC was dependent on the morphology of the anodized film. The composition of the electrolyte and the current density of the anodization treatment affected the SCC susceptibility of the AZ61 alloy. The best corrosion resistance and the lowest susceptibility to SCC were obtained for samples anodized in the borate-containing electrolyte at 30 mA.cm -2 . The smooth and compact surface morphology of the anodized film obtained in this condition was the main reason for the improved SCC behavior of the AZ61 alloy.
{"title":"Effect of Anodization on the Stress Corrosion Cracking Behavior of The AZ61 Magnesium Alloy in 0.1 M NaCl Solution","authors":"F. Okamoto, Mara Cristina Lopes Oliveira, Adenilson Almeida Silva, R. Droppa Jr, R. A. Antunes","doi":"10.1590/1980-5373-mr-2022-0357","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0357","url":null,"abstract":"In the present work, the AZ61 alloy, one of the most important commercial structural magnesium alloys, was anodized in three different alkaline electrolytes consisting of 3 M KOH + 0.15 M Na 2 SiO 3 + 0.1 M Na 2 B 4 O 7 .10H 2 O, 3 M KOH + 0.5 M Na 3 PO 4 and 3 M KOH + 0.50 M Na 2 SiO 3 . The treatment was conducted at two different current densities, 20 and 30 mA.cm -2 for 10 minutes. The anodized layers were characterized by scanning electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy. The corrosion resistance was assessed by potentiodynamic polarization tests. The SCC behavior was studied using slow strain rate tests in 0.1 M NaCl solution at room temperature. Conventional tensile tests were also conducted in air. The susceptibility to SCC was dependent on the morphology of the anodized film. The composition of the electrolyte and the current density of the anodization treatment affected the SCC susceptibility of the AZ61 alloy. The best corrosion resistance and the lowest susceptibility to SCC were obtained for samples anodized in the borate-containing electrolyte at 30 mA.cm -2 . The smooth and compact surface morphology of the anodized film obtained in this condition was the main reason for the improved SCC behavior of the AZ61 alloy.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"76 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67302142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1590/1980-5373-mr-2022-0205
L. Rosso Neto, C. H. Borgert, J. R. Oliveira, F. Grillo, Gabriel Valério Pereira Manfredi, J. Coleti, D. Espinosa, J. Tenório, David Batista Gesuino, Tiago E. A. Frizon, E. Junca
The use of alternative raw materials is essential for establishing a circular economy in the mineral and ironmaking sectors. Therefore, this study investigates the potential of lime sludge as fluxing material during pelletization and proposes an alternative route for the usage of waste. The pellets were manufactured with different binary basicity values (CaO/SiO 2 ) (0.15–0.45) and bentonite (0.5–0.7 wt%) and fixed carbon (0.5–1.1 wt%) contents. The results demonstrated that lime sludge has significant potential for application in pelletization. Pellet quality was evaluated using drop number, mechanical strength, tumble index, porosity, and kinetic analyses. Pellets with the optimal composition using lime sludge withstood 3.6 drops/pellet, a tumble test of 1.57 wt.%, and a mechanical strength test of 214.83 kgf/pellet and exhibited a porosity of 31.28%. Lime sludge did not influence the reducibility of the iron-ore pellets. In the temperature range of 800–900 °C, the reaction was controlled by diffusion, with E a between 179.89 and 233.10 kJ/mol.
{"title":"Green Ironmaking Industry: Production of Iron Pellets Using Lime Sludge","authors":"L. Rosso Neto, C. H. Borgert, J. R. Oliveira, F. Grillo, Gabriel Valério Pereira Manfredi, J. Coleti, D. Espinosa, J. Tenório, David Batista Gesuino, Tiago E. A. Frizon, E. Junca","doi":"10.1590/1980-5373-mr-2022-0205","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0205","url":null,"abstract":"The use of alternative raw materials is essential for establishing a circular economy in the mineral and ironmaking sectors. Therefore, this study investigates the potential of lime sludge as fluxing material during pelletization and proposes an alternative route for the usage of waste. The pellets were manufactured with different binary basicity values (CaO/SiO 2 ) (0.15–0.45) and bentonite (0.5–0.7 wt%) and fixed carbon (0.5–1.1 wt%) contents. The results demonstrated that lime sludge has significant potential for application in pelletization. Pellet quality was evaluated using drop number, mechanical strength, tumble index, porosity, and kinetic analyses. Pellets with the optimal composition using lime sludge withstood 3.6 drops/pellet, a tumble test of 1.57 wt.%, and a mechanical strength test of 214.83 kgf/pellet and exhibited a porosity of 31.28%. Lime sludge did not influence the reducibility of the iron-ore pellets. In the temperature range of 800–900 °C, the reaction was controlled by diffusion, with E a between 179.89 and 233.10 kJ/mol.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67301816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1590/1980-5373-mr-2022-0613
F. R. C. Macedo, R. M. Monção, J. Queiroz, M. S. Libório, J. D. Costa, L. S. Rossino, M. Danelon, M. Feitor, T. Costa, R. Sousa
In this work, plasma nitriding (PN) and cathode cage plasma deposition (CCPN) treatments were carried out with temperatures of 400 and 450 °C to evaluate the modifications caused on the surface of pure niobium samples. XRD, SEM, Vickers microhardness, and sphere-disk analyses were used to characterize the coatings’ composition, morphology, hardness, and wear resistance. The results showed that the treated samples increased hardness and wear resistance, with the sample submitted to CCPN at 450 °C presenting the best tribological behavior.
{"title":"Study of Surface Modification of Niobium Caused by Nitriding and Cathodic Cage Deposition","authors":"F. R. C. Macedo, R. M. Monção, J. Queiroz, M. S. Libório, J. D. Costa, L. S. Rossino, M. Danelon, M. Feitor, T. Costa, R. Sousa","doi":"10.1590/1980-5373-mr-2022-0613","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0613","url":null,"abstract":"In this work, plasma nitriding (PN) and cathode cage plasma deposition (CCPN) treatments were carried out with temperatures of 400 and 450 °C to evaluate the modifications caused on the surface of pure niobium samples. XRD, SEM, Vickers microhardness, and sphere-disk analyses were used to characterize the coatings’ composition, morphology, hardness, and wear resistance. The results showed that the treated samples increased hardness and wear resistance, with the sample submitted to CCPN at 450 °C presenting the best tribological behavior.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67304001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1590/1980-5373-mr-2022-0475
Fernando Luis Schiavon, Heloisa Zanardi, I. Zago, R. A. Angélico
The macroscopic properties of composite materials depend on the microscopic properties of the constituents and the geometric arrangement of their phases. Therefore, it is essential to predict heterogeneous materials’ mechanical properties by simulating microstructural finite element models. The present article aims to analyze particle reinforced composites composed of spherical alumina inclusions surrounded by a glass matrix using a tridimensional representative volume element. Herein, microstructures are artificially created considering a regular or random arrangement of the inclusions. Two materials systems previously studied in the literature were analyzed. The discretization of the models was performed to have periodic mesh, thus enabling the use of periodic boundary conditions. A finite element model is created using Abaqus software. Numerical results show that the macroscopic properties can be estimated with high accuracy for the temperature where linear matrix behavior stands. The predictions were compared to experimental data from the literature. The models with a regular arrangement of inclusions show a difference inferior to 10%, while random arrangements show a difference inferior to 3.9%. The developed numerical algorithms can be modified to include new features, such as other dispersed phase arrangements or nonlinear material behavior.
{"title":"Prediction of Elastic Parameters of Particle Reinforced Composites Using Finite Element Simulations","authors":"Fernando Luis Schiavon, Heloisa Zanardi, I. Zago, R. A. Angélico","doi":"10.1590/1980-5373-mr-2022-0475","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0475","url":null,"abstract":"The macroscopic properties of composite materials depend on the microscopic properties of the constituents and the geometric arrangement of their phases. Therefore, it is essential to predict heterogeneous materials’ mechanical properties by simulating microstructural finite element models. The present article aims to analyze particle reinforced composites composed of spherical alumina inclusions surrounded by a glass matrix using a tridimensional representative volume element. Herein, microstructures are artificially created considering a regular or random arrangement of the inclusions. Two materials systems previously studied in the literature were analyzed. The discretization of the models was performed to have periodic mesh, thus enabling the use of periodic boundary conditions. A finite element model is created using Abaqus software. Numerical results show that the macroscopic properties can be estimated with high accuracy for the temperature where linear matrix behavior stands. The predictions were compared to experimental data from the literature. The models with a regular arrangement of inclusions show a difference inferior to 10%, while random arrangements show a difference inferior to 3.9%. The developed numerical algorithms can be modified to include new features, such as other dispersed phase arrangements or nonlinear material behavior.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67303116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1590/1980-5373-mr-2022-0449
Marcelo Rodrigues, Maurício Maia Ribeiro, Robson Luis Baleeiro Cardoso, Ana Gabriele da Paixão Ferreira, Silmara Mota Cardoso, Jaciléa Campos da Silva, Roberto Paulo Barbosa Ramos, J. Rodrigues
The Digital Image Correlation (DIC) technique is an important method of evaluating material strain fields. Composite materials have inherently heterogeneous elastic properties, in the function of the different phases present in the composition, whereat the traditional techniques of deformation evaluation may not be sufficient to determine the mechanisms that eventually contribute to the failure of the material. The present work were evaluated, the tensile mechanical properties of polyester matrix composites loaded with an industrial residue of red mud, with a mass fraction of 20%. The properties were surveyed using the conventional technique of strain gauge and compared with the data obtained through DIC. The results showed that the DIC technique was accurate in monitoring the displacements and determining the average deformation of the tested specimens, in addition to providing ample deformation fields, for the evaluation of failure mechanisms throughout the sample request process.
{"title":"Determination of Tensile Properties of Polyester - Industrial Waste Red Mud Composites Using Digital Image Correlation (DIC)","authors":"Marcelo Rodrigues, Maurício Maia Ribeiro, Robson Luis Baleeiro Cardoso, Ana Gabriele da Paixão Ferreira, Silmara Mota Cardoso, Jaciléa Campos da Silva, Roberto Paulo Barbosa Ramos, J. Rodrigues","doi":"10.1590/1980-5373-mr-2022-0449","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0449","url":null,"abstract":"The Digital Image Correlation (DIC) technique is an important method of evaluating material strain fields. Composite materials have inherently heterogeneous elastic properties, in the function of the different phases present in the composition, whereat the traditional techniques of deformation evaluation may not be sufficient to determine the mechanisms that eventually contribute to the failure of the material. The present work were evaluated, the tensile mechanical properties of polyester matrix composites loaded with an industrial residue of red mud, with a mass fraction of 20%. The properties were surveyed using the conventional technique of strain gauge and compared with the data obtained through DIC. The results showed that the DIC technique was accurate in monitoring the displacements and determining the average deformation of the tested specimens, in addition to providing ample deformation fields, for the evaluation of failure mechanisms throughout the sample request process.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67303387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.1590/1980-5373-mr-2022-0362
Ozgur Poyraz
This study aims to contribute to the scientific knowledge by investigating the influence of build direction and post-curing on the material and part attributes of acrylonitrile butadiene styrene (ABS-like) like resins by photopolymerization based additive manufacturing (AM). Specimens were manufactured in different build directions with the parameters that offer the highest density. Two groups of specimens, one as-built and the other post-cured, were subjected to dimensional inspections, surface characterization, fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), hardness measurements, tensile tests, bending tests, Charpy impact tests and the obtained values were reported and benchmarked. It has been observed that the change in the build direction significantly affects the surface roughness and the average surface roughness of the samples produced in the vertical plane is much higher than those produced in the horizontal plane. It was demonstrated that post-curing has a negligible effect on part dimensions and density. It increases hardness, tensile modulus and flexural modulus while reducing elongation and impact resistance. The effects of post-curing on chemical and thermal properties were also compared and it was determined that it improves the thermal stability. In the absence of post-curing, vertical as-built specimens were observed to have higher strength than their horizontal counterparts.
{"title":"Influence of Build Direction and Post Processes on the Material and Part Attributes of Hard Resins Fabricated by Photopolymerization Based Additive Manufacturing","authors":"Ozgur Poyraz","doi":"10.1590/1980-5373-mr-2022-0362","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0362","url":null,"abstract":"This study aims to contribute to the scientific knowledge by investigating the influence of build direction and post-curing on the material and part attributes of acrylonitrile butadiene styrene (ABS-like) like resins by photopolymerization based additive manufacturing (AM). Specimens were manufactured in different build directions with the parameters that offer the highest density. Two groups of specimens, one as-built and the other post-cured, were subjected to dimensional inspections, surface characterization, fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), hardness measurements, tensile tests, bending tests, Charpy impact tests and the obtained values were reported and benchmarked. It has been observed that the change in the build direction significantly affects the surface roughness and the average surface roughness of the samples produced in the vertical plane is much higher than those produced in the horizontal plane. It was demonstrated that post-curing has a negligible effect on part dimensions and density. It increases hardness, tensile modulus and flexural modulus while reducing elongation and impact resistance. The effects of post-curing on chemical and thermal properties were also compared and it was determined that it improves the thermal stability. In the absence of post-curing, vertical as-built specimens were observed to have higher strength than their horizontal counterparts.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67302211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-17DOI: 10.1590/1980-5373-mr-2022-0386
Mu’ayyad M. Al-Shrida, M. Hayajneh, F. Al-Oqla
,
{"title":"Modeling and Investigation of the Influential Reinforcement Parameters on the Strength of Polypropylene Lignocellulosic Fiber Composites Using Analysis of Variances and Box-Cox Transformation Technique","authors":"Mu’ayyad M. Al-Shrida, M. Hayajneh, F. Al-Oqla","doi":"10.1590/1980-5373-mr-2022-0386","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0386","url":null,"abstract":",","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67302692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-14DOI: 10.1590/1980-5373-mr-2022-0061
E. Dul’kin, Michael Roth, F. Craciun, C. Galassi
9/65/35 PLZT relaxor was studied under a bias electric field using the acoustic emission method. It was established that the temperature of smeared dielectric constant maximum exhibits the V-shape, lying fully within the ergodic phase, as well as that the threshold electric field is found to be approximately the same as in both PMN-0.24PT and PFN-0.02PT relaxors. A reason of the latter phenomena is discussed from the viewpoint of incorporated ions properties.
{"title":"Non-trivial Behavior of Temperature of Dielectric Constant Maximum in (Pb/La)(Zr/Ti)O3 9/65/35 Relaxor Ferroelectric Ceramics Detected by Acoustic Emission","authors":"E. Dul’kin, Michael Roth, F. Craciun, C. Galassi","doi":"10.1590/1980-5373-mr-2022-0061","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0061","url":null,"abstract":"9/65/35 PLZT relaxor was studied under a bias electric field using the acoustic emission method. It was established that the temperature of smeared dielectric constant maximum exhibits the V-shape, lying fully within the ergodic phase, as well as that the threshold electric field is found to be approximately the same as in both PMN-0.24PT and PFN-0.02PT relaxors. A reason of the latter phenomena is discussed from the viewpoint of incorporated ions properties.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67300664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-14DOI: 10.1590/1980-5373-mr-2022-0433
G. Iulianelli, Lucas Viana Costa, Paulo Sergio C.P. da Silva, F. D. Santos
In this work, biodegradable biocomposites were developed using PLA/PHB blend as matrix and two types of microcrystalline cellulose as filler at three different contents. The biocomposites were evaluated regarding their thermal and morphological characteristics and molecular dynamic behavior. It was seen that cellulose addition did not promote significant changes in the Tm, Tc and Tcc in the matrix. On the other hand, XRD and TGA revealed that the addition of the highest content (7 wt%) of cellulose fillers resulted in a more significant decrease in crystallinity and thermal stability of the PLA/PHB matrix, suggesting a formation of filler aggregates. This indication was confirmed by TD-NMR, whose results pointed to a greater heterogeneity molecular in the samples containing higher cellulose contents. Therefore, this technique proved to be a relevant and complementary tool for the characterization of composites materials, contributing to determinate the most appropriate filler content introduced in a polymer matrix.
{"title":"Evaluation of Fully Biodegradable PLA/PHB Blend Filled with Microcrystalline Celluloses","authors":"G. Iulianelli, Lucas Viana Costa, Paulo Sergio C.P. da Silva, F. D. Santos","doi":"10.1590/1980-5373-mr-2022-0433","DOIUrl":"https://doi.org/10.1590/1980-5373-mr-2022-0433","url":null,"abstract":"In this work, biodegradable biocomposites were developed using PLA/PHB blend as matrix and two types of microcrystalline cellulose as filler at three different contents. The biocomposites were evaluated regarding their thermal and morphological characteristics and molecular dynamic behavior. It was seen that cellulose addition did not promote significant changes in the Tm, Tc and Tcc in the matrix. On the other hand, XRD and TGA revealed that the addition of the highest content (7 wt%) of cellulose fillers resulted in a more significant decrease in crystallinity and thermal stability of the PLA/PHB matrix, suggesting a formation of filler aggregates. This indication was confirmed by TD-NMR, whose results pointed to a greater heterogeneity molecular in the samples containing higher cellulose contents. Therefore, this technique proved to be a relevant and complementary tool for the characterization of composites materials, contributing to determinate the most appropriate filler content introduced in a polymer matrix.","PeriodicalId":18331,"journal":{"name":"Materials Research-ibero-american Journal of Materials","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67302648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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