Pub Date : 2023-09-04DOI: 10.1590/0104-1428.20230010
Juliana Paes Leme de Mello Sousa, R. N. Oliveira, Antonia Monica Neres Santos, O. Gamallo, Leonardo Sales Araújo, A. Middea, Y. P. Cid, Rosane Nora Castro
Propolis is a resinous product collected by honeybees with a complex chemical composition. Sodium carboxymethylcellulose is a polymer commonly used in wound care. The goal of the present work was to produce and characterize NaCMC membranes loaded with extract of Brazilian brown propolis (CMC-P). Flavonoids and phenolic acids were identified in the propolis extracts, where the main identified substance was kaempferide. The brown propolis extracted was active against S. aureus . The low swelling capacity and high gel fraction of CMC-P would be the consequence of propolis (responsible for a hydrophobic barrier) filling the pores of the membrane. Propolis could be anchoring the NaCMC chains (as observed by FTIR) due to interaction between components, which is corroborated by the CMC-P sample degrading less than the CMC sample (>400ºC). There was non-linear diffusion release kinetics for most phenolic substances of the propolis extract. The CMC-P sample presents potential as a dressing material.
{"title":"Superabsorbent biodegradable CMC membranes loaded with propolis: Peppas-Sahlin kinetics release","authors":"Juliana Paes Leme de Mello Sousa, R. N. Oliveira, Antonia Monica Neres Santos, O. Gamallo, Leonardo Sales Araújo, A. Middea, Y. P. Cid, Rosane Nora Castro","doi":"10.1590/0104-1428.20230010","DOIUrl":"https://doi.org/10.1590/0104-1428.20230010","url":null,"abstract":"Propolis is a resinous product collected by honeybees with a complex chemical composition. Sodium carboxymethylcellulose is a polymer commonly used in wound care. The goal of the present work was to produce and characterize NaCMC membranes loaded with extract of Brazilian brown propolis (CMC-P). Flavonoids and phenolic acids were identified in the propolis extracts, where the main identified substance was kaempferide. The brown propolis extracted was active against S. aureus . The low swelling capacity and high gel fraction of CMC-P would be the consequence of propolis (responsible for a hydrophobic barrier) filling the pores of the membrane. Propolis could be anchoring the NaCMC chains (as observed by FTIR) due to interaction between components, which is corroborated by the CMC-P sample degrading less than the CMC sample (>400ºC). There was non-linear diffusion release kinetics for most phenolic substances of the propolis extract. The CMC-P sample presents potential as a dressing material.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67123324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-04DOI: 10.1590/0104-1428.20210010
Sanbao Dong, Wen Tian, Wenting Qiang, Long Jiao, Jie Zhang, Gang Chen
The surfactant-polymer-based (S/P) fracturing fluid combines the advantages of the surfactant-based and polymer-based fracturing fluids. In this study, the synergistic tackifying of cationic surfactants and carboxymethyl hydroxyethyl cellulose and the potential application in hydraulic fracturing fluid was investigated. Firstly, cetyltrimethylammonium chloride (CTAC) and salicylic acid (SA) with a weight ratio of 4:1 were optimized as the main agent of the small molecule surfactant gel, which was then mixed with carboxymethyl 2-hydroxyethyl ether cellulose (CMHEC) and salicylic acid (SA) to obtain the S/P gel. The proppant suspension performance, gel-breaking properties, salt-resistance and thermal stability of the optimized S/P were evaluated to confirm their potential application in the hydraulic fracturing fluid. These results showed that the performance of the S/P fracturing fluid system was much better than the performance of the surfactant fracturing fluid and also the performance of polymer fracturing
{"title":"Fabrication of fracturing fluid with cationic surfactants and carboxymethyl hydroxyethyl cellulose","authors":"Sanbao Dong, Wen Tian, Wenting Qiang, Long Jiao, Jie Zhang, Gang Chen","doi":"10.1590/0104-1428.20210010","DOIUrl":"https://doi.org/10.1590/0104-1428.20210010","url":null,"abstract":"The surfactant-polymer-based (S/P) fracturing fluid combines the advantages of the surfactant-based and polymer-based fracturing fluids. In this study, the synergistic tackifying of cationic surfactants and carboxymethyl hydroxyethyl cellulose and the potential application in hydraulic fracturing fluid was investigated. Firstly, cetyltrimethylammonium chloride (CTAC) and salicylic acid (SA) with a weight ratio of 4:1 were optimized as the main agent of the small molecule surfactant gel, which was then mixed with carboxymethyl 2-hydroxyethyl ether cellulose (CMHEC) and salicylic acid (SA) to obtain the S/P gel. The proppant suspension performance, gel-breaking properties, salt-resistance and thermal stability of the optimized S/P were evaluated to confirm their potential application in the hydraulic fracturing fluid. These results showed that the performance of the S/P fracturing fluid system was much better than the performance of the surfactant fracturing fluid and also the performance of polymer fracturing","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67120533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-04DOI: 10.1590/0104-1428.20220010
S. Scagliusi, Elizabeth Leite Carvalho Cardoso, F. Esper, A. B. Lugão, Helio Wiebeck
Due to the technical evolution of tires, currently most automotive tires do not have an inner tube. However, truck, motorcycle and bicycle tires still use tires with inner tubes, mostly made of synthetic elastomeric material, which guarantees good potential for air restriction or longer periods for tire pressure failure. This work aims to study changes in the mechanical properties of a truck inner tire, after its exposure to gamma rays, to promote the subsequent recycling of the material. The choice of ionizing radiation is due to its ability to modify the structure and properties of materials, in addition to its applicability in recycling/recovering rubber. For the characterization of the samples, doses of 5, 10, 15, 20, 25 and 30 kGy were applied, and after irradiation as a sample, they were tested using the following characterization methods: traction and elongation at break, hardness, thermal aging and elemental analysis. Observed that is a decrease in the values of the mechanical properties of the samples after irradiation, mainly at doses greater than 10 kGy.
{"title":"Study of mechanical properties of inner tubes exposed to gamma radiation","authors":"S. Scagliusi, Elizabeth Leite Carvalho Cardoso, F. Esper, A. B. Lugão, Helio Wiebeck","doi":"10.1590/0104-1428.20220010","DOIUrl":"https://doi.org/10.1590/0104-1428.20220010","url":null,"abstract":"Due to the technical evolution of tires, currently most automotive tires do not have an inner tube. However, truck, motorcycle and bicycle tires still use tires with inner tubes, mostly made of synthetic elastomeric material, which guarantees good potential for air restriction or longer periods for tire pressure failure. This work aims to study changes in the mechanical properties of a truck inner tire, after its exposure to gamma rays, to promote the subsequent recycling of the material. The choice of ionizing radiation is due to its ability to modify the structure and properties of materials, in addition to its applicability in recycling/recovering rubber. For the characterization of the samples, doses of 5, 10, 15, 20, 25 and 30 kGy were applied, and after irradiation as a sample, they were tested using the following characterization methods: traction and elongation at break, hardness, thermal aging and elemental analysis. Observed that is a decrease in the values of the mechanical properties of the samples after irradiation, mainly at doses greater than 10 kGy.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67121620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-28DOI: 10.1590/0104-1428.20230001
Willian Rodrigo Schuster, S. Pezzin, F. H. Lafratta
Tricomponent epoxy-matrix nanocomposites were prepared by airbrushing multiwalled carbon nanotubes (MWCNT) on glass fiber fabric (GF), aiming to establish a scalable route to produce electromagnetic interference (EMI) materials. The MWCNT deposition on GF by airbrushing was evaluated by scanning electron microscopy (SEM), showing a very reasonable dispersion even at high MWCNT concentrations. Electrical conductivity measurements have shown a maximum of 1.2x10 -3 S/cm for GF with 3.4 wt% MWCNT. Electromagnetic shielding response for GF airbrushed with MWCNT and epoxy-matrix nanocomposites were analyzed considering reflection, absorption and transmission mechanisms and have shown an increasing trend as the MWCNT content increases, reaching the best result of 7.6 dB of shielding effectiveness (SE) in X-band spectra for the composite with 3.4 wt% MWCNT. The results showed that the airbrushing process can be a promising and easy route for manufacturing of MWCNT/GF/epoxy nanocomposites.
{"title":"Airbrushing of carbon nanotubes on glass fibers for electromagnetic shielding epoxy composites","authors":"Willian Rodrigo Schuster, S. Pezzin, F. H. Lafratta","doi":"10.1590/0104-1428.20230001","DOIUrl":"https://doi.org/10.1590/0104-1428.20230001","url":null,"abstract":"Tricomponent epoxy-matrix nanocomposites were prepared by airbrushing multiwalled carbon nanotubes (MWCNT) on glass fiber fabric (GF), aiming to establish a scalable route to produce electromagnetic interference (EMI) materials. The MWCNT deposition on GF by airbrushing was evaluated by scanning electron microscopy (SEM), showing a very reasonable dispersion even at high MWCNT concentrations. Electrical conductivity measurements have shown a maximum of 1.2x10 -3 S/cm for GF with 3.4 wt% MWCNT. Electromagnetic shielding response for GF airbrushed with MWCNT and epoxy-matrix nanocomposites were analyzed considering reflection, absorption and transmission mechanisms and have shown an increasing trend as the MWCNT content increases, reaching the best result of 7.6 dB of shielding effectiveness (SE) in X-band spectra for the composite with 3.4 wt% MWCNT. The results showed that the airbrushing process can be a promising and easy route for manufacturing of MWCNT/GF/epoxy nanocomposites.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67123061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The thermo-mechanical degradation of PET during extrusion was studied in the transient state. Active agents, water, causing hydrolysis by chain scission and pyromellitic dianhydride PMDA, causing chain extension, were added to the extrusion flow as pulses. They change the PET molecular weight, affecting its the melt flow elasticity, which was followed in-line by a rheo-optical detector set in an instrumented slit-die, measuring synchronously, pressure drop and flow birefringence ( 12 n ∆ ). The effect of the extrusion shearing level, set by 90º kneading blocks with different lengths, was also quantified. The results, as of residence time distribution curves, show the degree of thermo-mechanical degradation as hydrolysis and chain extension for each pulse type and concentration. Thus, assuming collinearity and full birefringence orientation along the melt flow the first normal stress difference 1 N can be monitored in-line.
{"title":"In-line rheo-optical characterization of PET hydrolysis and chain extension during extrusion","authors":"Luciana Assumpção Bicalho, Sebastião Vicente Canevarolo Junior","doi":"10.1590/0104-1428.20220066","DOIUrl":"https://doi.org/10.1590/0104-1428.20220066","url":null,"abstract":"The thermo-mechanical degradation of PET during extrusion was studied in the transient state. Active agents, water, causing hydrolysis by chain scission and pyromellitic dianhydride PMDA, causing chain extension, were added to the extrusion flow as pulses. They change the PET molecular weight, affecting its the melt flow elasticity, which was followed in-line by a rheo-optical detector set in an instrumented slit-die, measuring synchronously, pressure drop and flow birefringence ( 12 n ∆ ). The effect of the extrusion shearing level, set by 90º kneading blocks with different lengths, was also quantified. The results, as of residence time distribution curves, show the degree of thermo-mechanical degradation as hydrolysis and chain extension for each pulse type and concentration. Thus, assuming collinearity and full birefringence orientation along the melt flow the first normal stress difference 1 N can be monitored in-line.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67122429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-14DOI: 10.1590/0104-1428.20230005
B. C. Bal
This study used a high-density polyethylene (HDPE) polymer matrix, pine-wood flour (PWF) and walnut-shell flour (WSF) to produce wood–plastic composite (WPC) boards. The PWF and WSF filler amounts were adjusted to 20%, 30%, and 40% by weight. Some of the mechanical properties of the produced composite boards were comparatively investigated, such as the flexural strength, flexural modulus, deformation at break, tensile strength, tensile modulus, and elongation at break. Flexural tests and tensile tests were performed according to ASTM D790 and ASTM D638, respectively. According to the data obtained, the flexural strength, deformation at break, tensile strength, and elongation at break decreased as the filler content increased. In addition, the flexural modulus values of all the test groups increased with the filler content. However, the tensile modulus values of the test groups that used the WSF filler were smaller than those of the groups without filler.
{"title":"Some mechanical properties of WPCs with wood flour and walnut shell flour","authors":"B. C. Bal","doi":"10.1590/0104-1428.20230005","DOIUrl":"https://doi.org/10.1590/0104-1428.20230005","url":null,"abstract":"This study used a high-density polyethylene (HDPE) polymer matrix, pine-wood flour (PWF) and walnut-shell flour (WSF) to produce wood–plastic composite (WPC) boards. The PWF and WSF filler amounts were adjusted to 20%, 30%, and 40% by weight. Some of the mechanical properties of the produced composite boards were comparatively investigated, such as the flexural strength, flexural modulus, deformation at break, tensile strength, tensile modulus, and elongation at break. Flexural tests and tensile tests were performed according to ASTM D790 and ASTM D638, respectively. According to the data obtained, the flexural strength, deformation at break, tensile strength, and elongation at break decreased as the filler content increased. In addition, the flexural modulus values of all the test groups increased with the filler content. However, the tensile modulus values of the test groups that used the WSF filler were smaller than those of the groups without filler.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67123207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-14DOI: 10.1590/0104-1428.20220024
S. O. L. Souza, S. M. Oliveira, Catarina Paschoalini Lehman, M. C. Silva, Luciana Maria Silva, R. Oréfice
Tumor organoids have great potential as a 3D in vitro system to model cancer. In this work, we studied how the structure of hydrogels based on gelatin with methacryloyl groups (GeIMA) can affect their usage in tumor organoids. To this end, gelatin hydrogels with different levels of methacrylation and with cellulose nanocrystals (NCC) or reduced graphene oxide (rGO) were prepared and used to encapsulate human colon carcinoma cells (RKO). Mechanical properties of the hydrogels were measured in dynamic conditions at 37°C and water. Results showed that NCC was able to provide higher mechanical stability to the hydrogels. RKO cells embedded in GelMA were able to proliferate within the hydrogels, leading to the formation of groups of cells after 48 h. GelMA with higher crosslink densities and NCC tended to show higher cell population as possibly due to the higher level of stability and rigidity displayed by these hydrogels.
{"title":"Tuning the structure and properties of cell-embedded gelatin hydrogels for tumor organoids","authors":"S. O. L. Souza, S. M. Oliveira, Catarina Paschoalini Lehman, M. C. Silva, Luciana Maria Silva, R. Oréfice","doi":"10.1590/0104-1428.20220024","DOIUrl":"https://doi.org/10.1590/0104-1428.20220024","url":null,"abstract":"Tumor organoids have great potential as a 3D in vitro system to model cancer. In this work, we studied how the structure of hydrogels based on gelatin with methacryloyl groups (GeIMA) can affect their usage in tumor organoids. To this end, gelatin hydrogels with different levels of methacrylation and with cellulose nanocrystals (NCC) or reduced graphene oxide (rGO) were prepared and used to encapsulate human colon carcinoma cells (RKO). Mechanical properties of the hydrogels were measured in dynamic conditions at 37°C and water. Results showed that NCC was able to provide higher mechanical stability to the hydrogels. RKO cells embedded in GelMA were able to proliferate within the hydrogels, leading to the formation of groups of cells after 48 h. GelMA with higher crosslink densities and NCC tended to show higher cell population as possibly due to the higher level of stability and rigidity displayed by these hydrogels.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67121826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-14DOI: 10.1590/0104-1428.20230029
M. M. Takematsu, A. F. Baruel, S. N. Cassu, M. F. Diniz, D. Graves, R. C. Dutra
Composites are relevant to high-performance materials in the aerospace sector and have attracted the attention of the scientific and technological communities. Bentonites present very fine granulometry which enables their use in composites. This study showed the development of water absorbent composite based on sodium polyacrylate, bentonite coated by epoxy resin. Since there are gaps in the quantification of composite materials by near-infrared spectroscopy, especially by reflectance analysis (NIRA), this paper shows a quantification methodology (A 7200 /A 5202 ) of sodium polyacrylate and bentonite. The methodology error found was 1.45% (95% of coefficient of determination). The effectiveness of the developed infrared methodology was verified showing that values are close to the nominal, especially for lower bentonite content. Besides, scanning electron microscopy (SEM) and universal attenuated total reflection (UATR) analysis evidenced the coating with the epoxy resin. Such development ensures rapid and precise methodologies that can be applied to the quality control of composite materials.
{"title":"Development and characterization of sodium polyacrylate/bentonite hydrogel with epoxy resin coating","authors":"M. M. Takematsu, A. F. Baruel, S. N. Cassu, M. F. Diniz, D. Graves, R. C. Dutra","doi":"10.1590/0104-1428.20230029","DOIUrl":"https://doi.org/10.1590/0104-1428.20230029","url":null,"abstract":"Composites are relevant to high-performance materials in the aerospace sector and have attracted the attention of the scientific and technological communities. Bentonites present very fine granulometry which enables their use in composites. This study showed the development of water absorbent composite based on sodium polyacrylate, bentonite coated by epoxy resin. Since there are gaps in the quantification of composite materials by near-infrared spectroscopy, especially by reflectance analysis (NIRA), this paper shows a quantification methodology (A 7200 /A 5202 ) of sodium polyacrylate and bentonite. The methodology error found was 1.45% (95% of coefficient of determination). The effectiveness of the developed infrared methodology was verified showing that values are close to the nominal, especially for lower bentonite content. Besides, scanning electron microscopy (SEM) and universal attenuated total reflection (UATR) analysis evidenced the coating with the epoxy resin. Such development ensures rapid and precise methodologies that can be applied to the quality control of composite materials.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67123749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-11DOI: 10.1590/0104-1428.20230018
Menderes Koyunucu, Göksel Ulay
In this study, walnut shell particles obtained through the grinding of walnut shells were used as a reinforcing material and pumice powder as a filler for developing epoxy-based composites characterized by reduced flammability. Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), and Underwriters Laboratories (UL)-94 vertical tests were carried out for evaluating the effectiveness of these pumice powder treatments. Under the UL-94 vertical test, composites (S1, S2, S3, S4, S5 and S6) with 20% pumice powder (i.e., by mass content of walnut particles were not self-extinguished, and could not be classified. S7 and S8 composites (40wt% and 50%) assigned a V-2 rating, which was the least flammable composite However, the mechanical tensile tests showed that the pumice powder treated composites increased their tensile strength. The morphological analysis showed an enhancement of the interfacial adhesion of the composites achieved by pumice powder.
{"title":"Thermal and flammability behavior of walnut shell reinforced epoxy composites","authors":"Menderes Koyunucu, Göksel Ulay","doi":"10.1590/0104-1428.20230018","DOIUrl":"https://doi.org/10.1590/0104-1428.20230018","url":null,"abstract":"In this study, walnut shell particles obtained through the grinding of walnut shells were used as a reinforcing material and pumice powder as a filler for developing epoxy-based composites characterized by reduced flammability. Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), and Underwriters Laboratories (UL)-94 vertical tests were carried out for evaluating the effectiveness of these pumice powder treatments. Under the UL-94 vertical test, composites (S1, S2, S3, S4, S5 and S6) with 20% pumice powder (i.e., by mass content of walnut particles were not self-extinguished, and could not be classified. S7 and S8 composites (40wt% and 50%) assigned a V-2 rating, which was the least flammable composite However, the mechanical tensile tests showed that the pumice powder treated composites increased their tensile strength. The morphological analysis showed an enhancement of the interfacial adhesion of the composites achieved by pumice powder.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67123391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-11DOI: 10.1590/0104-1428.20220112
Michelle Félix de Andrade, I. D. L. Silva, Viviane Fonseca Caetano, Gisely Alves da Silva, Luiz Emílio Pessoa Timeni de Moraes Filho, Y. B. Almeida, G. Vinhas
The use of natural antimicrobial additives, such as orange essential oil (OO), can be a promising possibility to increase food shelf life with the aid of active packaging. This study aimed to develop an active packaging using orange oil and PBAT – poly (butylene adipate co-terephthalate) to store mozzarella cheese produced by a fine film extruder with 5, 10, and 15% OO (w/w). In the results, D-limonene was oil’s main constituent with antimicrobial activity against E. aerogenes, E. coli, and S. aureus. The addition of the oil did not alter the thermal stability of the film. The water vapor permeability increased with increasing oil concentration. All films presented high strength. However, films with higher OO concentrations favored the degradation process, as observed in the activation energy. The active packaging added with 15% OO (PBAT15) was efficient, reducing microbial growth up to 6 days of storage of mozzarella cheese.
{"title":"Active antimicrobial extruded films for mozzarella cheese from poly (butylene adipate co-terephthalate) (PBAT) and orange oil","authors":"Michelle Félix de Andrade, I. D. L. Silva, Viviane Fonseca Caetano, Gisely Alves da Silva, Luiz Emílio Pessoa Timeni de Moraes Filho, Y. B. Almeida, G. Vinhas","doi":"10.1590/0104-1428.20220112","DOIUrl":"https://doi.org/10.1590/0104-1428.20220112","url":null,"abstract":"The use of natural antimicrobial additives, such as orange essential oil (OO), can be a promising possibility to increase food shelf life with the aid of active packaging. This study aimed to develop an active packaging using orange oil and PBAT – poly (butylene adipate co-terephthalate) to store mozzarella cheese produced by a fine film extruder with 5, 10, and 15% OO (w/w). In the results, D-limonene was oil’s main constituent with antimicrobial activity against E. aerogenes, E. coli, and S. aureus. The addition of the oil did not alter the thermal stability of the film. The water vapor permeability increased with increasing oil concentration. All films presented high strength. However, films with higher OO concentrations favored the degradation process, as observed in the activation energy. The active packaging added with 15% OO (PBAT15) was efficient, reducing microbial growth up to 6 days of storage of mozzarella cheese.","PeriodicalId":20282,"journal":{"name":"Polimeros-ciencia E Tecnologia","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67122848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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