AbstractAbstract
[en] In this work, nanocomposites were developed and evaluated using high-density bio polyethylene (BPEAD)/Cloisite 20A (3 and 6%)/commercial antimicrobial additive (0,5 and 1%) containing 1% of zinc pyrithione dispersed in vinyl acetate (EVA). The samples were prepared in a single screw extruder using the melt intercalation technique and then by flat extrusion to obtain the films. X-ray diffraction (XRD) showed an increase in basal spacing and exfoliation of the structure of some films. The Fourier Transform Infrared Spectroscopy (FTIR) analysis illustrated the main functional groups for BHDPE and EVA. Thermal analysis indicated that BHDPE degradation did not change with organoclay addition, but crystallinity increased. The mechanical properties showed an increase in the elastic modulus and a decrease in maximum tensile strength. This work contributes to the development and improvement of the natural properties of BHDPE in order to enlarge its applications. (author)
Primary Subject
Source
Available from: https://www.scielo.br/j/po/a/3YZR3FdNgmy6VKSRLJ6SDgK/?format=pdf& lang=en
Record Type
Journal Article
Journal
Polimeros (Online); ISSN 1678-5169; ; v. 32(2); 8 p
Country of publication
ACETIC ACID ESTERS, ANTI-INFECTIVE AGENTS, CARBOXYLIC ACID ESTERS, CHEMICAL ANALYSIS, COHERENT SCATTERING, DIFFRACTION, DRUGS, ELEMENTS, ESTERS, GRAVIMETRIC ANALYSIS, INTEGRAL TRANSFORMATIONS, MATERIALS, MECHANICAL PROPERTIES, METALS, MINERALS, NANOMATERIALS, ORGANIC COMPOUNDS, ORGANIC POLYMERS, POLYMERS, POLYOLEFINS, QUANTITATIVE CHEMICAL ANALYSIS, SCATTERING, SILICATE MINERALS, SPECTRA, THERMAL ANALYSIS, TRANSFORMATIONS
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AbstractAbstract
[en] Bio-high density polyethylene (BHDPE) films with organoclay and antimicrobial additives (zinc pyrithione) were evaluated. The composites were prepared in a single-screw extruder using the melt intercalation technique, and the films were obtained by flat extrusion. The diffractograms indicated the formation of an intercalated nanocomposite (BHDPE/6 wt% of clay). Infrared spectra suggested that the polymer predominates over the antimicrobial agent bands. Thermal stability was slightly reduced by up to 3°C. The clay and antimicrobial agent reduced the melting point and crystallinity of BHDPE by up to 12 °C and 13.3%, respectively. In addition, the presence of clay and antimicrobial agent significantly (p < 0.05) affected all mechanical properties. Proliferation of Staphylococcus aureus demonstrated that both evaluated additives did not significantly (p > 0.05) inhibit microbial growth. The results emphasize a promising application of the films for packaging that does not require antimicrobial control, with films highlighted by 6 wt% of clay. (author)
Primary Subject
Source
Available from: https://www.scielo.br/j/po/a/QZHLshCMThG9QQXmVmYGCTh/?format=pdf& lang=en
Record Type
Journal Article
Journal
Polimeros (Online); ISSN 1678-5169; ; v. 34(1); 9 p
Country of publication
ANTI-INFECTIVE AGENTS, CHEMICAL ANALYSIS, COHERENT SCATTERING, DIFFRACTION, DRUGS, ELEMENTS, GRAVIMETRIC ANALYSIS, INTEGRAL TRANSFORMATIONS, MATERIALS, MECHANICAL PROPERTIES, METALS, MINERALS, NANOMATERIALS, ORGANIC COMPOUNDS, ORGANIC POLYMERS, PHYSICAL PROPERTIES, POLYMERS, POLYOLEFINS, QUANTITATIVE CHEMICAL ANALYSIS, SCATTERING, SILICATE MINERALS, SPECTRA, THERMAL ANALYSIS, TRANSFORMATIONS
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Silva, Raquel do Nascimento; Oliveira, Thainá Araújo de; Conceição, Isaias Damasceno da; Araque, Luis Miguel; Alves, Tatianny Soares; Barbosa, Renata, E-mail: rrenatabarbosa@yahoo.com2018
AbstractAbstract
[en] Studies about in vitro biodegradation of polymers have grown considerably due to the wide application of biodegradable polymers in biomedical areas. The objective of this study was to prepare bionanocomposites films of PHB, PEG, and organoclays by solution intercalation, and to evaluate the morphology, structure, hydrolytic degradation through FTIR and the calculation of carbonyl content. The results showed that bionanocomposites displayed intermediated dispersion of the filler, the polymer chains were intercalated into the organoclay layers and was observed some degree of exfoliation. There was an influence of PEG and of the clay on the degradation of the polymer, this fact was observed due to the decrease in the intensity of PHB carbonyl band in the region around 1275 cm-1, affecting the amorphous and crystalline regions of the polymer. This reduction can be associated with the increase in hydrophilicity of the polymer caused by the presence of the PEG and clay, suggesting the possibility of increasing the biodegradability of the pure polymer. In future research, there will be made characterizations to know if these materials can be used in medical devices. (author)
Primary Subject
Source
Available from: https://www.scielo.br/pdf/po/v28n4/0104-1428-po-28-4-348.pdf
Record Type
Journal Article
Journal
Polimeros (Online); ISSN 1678-5169; ; v. 28(4); 7 p
Country of publication
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Conceição, Isaías Damasceno da; Silva, Lucas Rafael Carneiro da; Alves, Tatianny Soares; Silva, Heurison de Sousa e; Barbosa, Renata; Sousa, Rômulo Ribeiro Magalhães de, E-mail: rrenatabarbosa@yahoo.com2019
AbstractAbstract
[en] Polyethylene (PE) is a polymer that has a low adhesion property, which is related to its low surface energy. However, the plasma treatment aims the modification of the surface properties without affecting the polymer structure. In this sense, the objective of this work was to prepare biocomposite films via flat extrusion with Green PE matrix and Expanded Vermiculite Clay (VMT), contents of 1, 3 and 6%. The films were treated by plasma in two different ways: Oxygen (O2 ) atmosphere (Condition 1); and Argon/Hydrogen (Ar/H2) atmosphere followed by a plasma treatment under O2 atmosphere (Condition 2). The results of the contact angle measurements indicated that the incorporation of VMT and the conditions used for plasma treatment increased the films wettability due to the hydrophilic character of VMT and also as a consequence of the plasma. In contrast, the XRD diffractograms indicated that there were no significant changes in the films structure. (author)
Primary Subject
Source
Available from: https://www.scielo.br/pdf/mr/v22s1/1516-1439-mr-22-s1-e20180918.pdf
Record Type
Journal Article
Journal
Materials Research (Sao Carlos, Online); ISSN 1980-5373; ; v. 22(suppl.1); 7 p
Country of publication
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AbstractAbstract
[en] In this work, biocomposites of poly (3-hydroxybutyrate) (PHB) / calcium carbonate from Rhea Americana eggshells were prepared and the effects of the addition of the inorganic filler in the polymeric matrix were assessed. The residue (powder) of the eggshell calcined at 400 deg C or in natura was inserted into a PHB solution for preparation of films via casting. Powder samples were characterized by X-Ray Fluorescence (XRF), X-Ray diffraction (XRD) and Thermogravimetry (TG/ DTG) and films were characterized by X-Ray diffraction (XRD), Scanning Electron Microscopy (SEM) and biodegradation tests according to the ASTM G 160-03 norm: the results were reported as weight loss and visual inspection by optical microscopy (OM). From the results of the XDR, it was perceived that the peaks in the diffractograms of the powder obtained by milling the Rhea Americana eggshells corresponded to the diffraction patterns of the Calcite crystals, which is a calcium carbonate polyform, and that the calcination preserved the crystalline structure, maintaining the calcium carbonate in the samples. For the biocomposites, a peak characteristic to the calcium carbonate in 29.57º was detected, indicating the insertion of the filler to the polymer matrix. Through SEM the presence of small agglomerates, probably due to polymer particles that were not dissolved, was observed for the pure PHB film. With the addition of the filler in natura a greater porosity was formed in the surface of the biocomposite films, and with the calcined filler, homogeneous films with reduced porosity were obtained. From the weight loss and OM results, it was observed that the filler inserted into the polymeric matrix catalyzes the biodegradation process up to 60 days evaluation in different ways, depending on the type of sample used. (author)
Primary Subject
Source
Available online http://www.scielo.br/pdf/mr/v21n4/1516-1439-mr-21-04-e20170792.pdf
Record Type
Journal Article
Journal
Materials Research (Sao Carlos, Online); ISSN 1980-5373; ; v. 21(4); p. 1-10
Country of publication
ALKALINE EARTH METAL COMPOUNDS, CALCIUM COMPOUNDS, CARBON COMPOUNDS, CARBONATES, CHEMICAL ANALYSIS, CHEMICAL REACTIONS, COHERENT SCATTERING, DECOMPOSITION, DIFFRACTION, ELECTRON MICROSCOPY, FABRICATION, GRAVIMETRIC ANALYSIS, MATERIALS, MICROSCOPY, NONDESTRUCTIVE ANALYSIS, OXYGEN COMPOUNDS, PYROLYSIS, QUANTITATIVE CHEMICAL ANALYSIS, SCATTERING, THERMAL ANALYSIS, THERMOCHEMICAL PROCESSES, X-RAY EMISSION ANALYSIS
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Alves, Tatianny Soares; Barbosa, Renata; Carvalho, Laura Hecker de; Canedo, Eduardo Luis, E-mail: tsaeng3@yahoo.com.br2014
AbstractAbstract
[en] The flammabilities of nanocomposites made with three polypropylene grades (homo and copolymers) with 5 wt % of organoclay (Cloisite 20A), 5 or 15 wt % of maleated polypropylene as compatibilizer, and 0, 0.5 or 1 wt % of cis-13-docosenamide (Erucamide) as co-intercalant, were studied using the horizontal burning test UL94HB. Masterbatches prepared in an internal mixer were diluted in the polypropylene matrix using a corotating twin-screw extruder, with different screw configurations and operating at 240 or 480 rpm. Results indicate that the high burning rate of the composites was not affected by the processing conditions. For all formulations was observed a significant reduction in smoke release, lack of dripping and the formation of a char surface layer, that protected the core of the samples. (author)
Original Title
Inflamabilidade de nanocompositos de polipropileno/argila organofilica
Primary Subject
Source
Available from http://www.scielo.br/pdf/po/v24n3/aop_polimerosao1466.pdf
Record Type
Journal Article
Journal
Polimeros (Sao Carlos); ISSN 0104-1428; ; v. 24(3); p. 307-313
Country of publication
LanguageLanguage
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AbstractAbstract
[en] The present work investigates the aquatic biodegradation of poly(3-hydroxybutyrate) (PHB)/nanoclay bionanocomposites containing PP-g-MA as compatibilizing agent. Both pristine and organically modified (Cloisite20A®) montmorillonite clay were used as fillers in different content (1 and 3 wt%). The bionanocomposites were prepared by melt intercalation in a single screw extruder. There after films (50x50x0.5mm) were prepared by compression and assessed by X-ray diffraction. Aquatic biodegradation of the films was appraised by visual inspection, optical microscopy, counting and identification of bacteria. Results proposed that the water of the Parnaíba River in the city of Teresina (Piauí, Brazil) has microorganisms (Pseudomonas putida and Pseudomonas aeruginosa) capable of degrading these bionanocomposite films, particularly the films with 3 wt% organoclay. Our data indicated the bacteria Pseudomonas aeruginosa degraded dexterously all the films. This work collaborates with the preservation of the environment and expands the use of bionanocomposites in expendable items with the development of films with properties favorable to biodegradation in aquatic environments. It is believed that PHB/clay/PP-g-MA films emerge as a promising alternative for the packaging industry. (author)
Primary Subject
Source
Available from: https://www.scielo.br/j/mr/a/GnHgpbrfFJPRQhxPkLV7WPk/?format=pdf& lang=en
Record Type
Journal Article
Journal
Materials Research (Sao Carlos, Online); ISSN 1980-5373; ; v. 26; 16 p
Country of publication
BACTERIA, CHEMICAL ANALYSIS, CHEMICAL REACTIONS, CLAYS, COHERENT SCATTERING, DECOMPOSITION, DIFFRACTION, ECOSYSTEMS, GRAVIMETRIC ANALYSIS, INORGANIC ION EXCHANGERS, ION EXCHANGE MATERIALS, MATERIALS, MICROORGANISMS, MICROSCOPY, MINERALS, NANOMATERIALS, PHASE TRANSFORMATIONS, QUANTITATIVE CHEMICAL ANALYSIS, SCATTERING, SILICATE MINERALS, THERMAL ANALYSIS
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AbstractAbstract
[en] The use of polymer blends and composites based on fossil-based and bio-based polymers has become an important environmentally protective alternative for common use and disposable plastics applications such as packaging, bottles and trays. The disposal of these more degradable products, however, may also harm the environment and, therefore, recycling these systems becomes relevant. Recycling involves reprocessing which can significantly change the morphology and properties of polymeric products. Therefore, this study deals with the effects of reprocessing cycles on the properties and morphology of blends and nanocomposites based on fossil and bio-based polymers. The systems investigated were: a) neat polypropylene (PP), b) a polypropylene/poly(3-hydroxybutyrate) (PP/PHB) blend and c) PP/PHB/organoclay nanocomposite compatibilized with polypropylene-g-maleic anhydride (PP-g-MA) and erucamide. These materials were submitted to up to seven extrusion cycles in a single screw extruder operating at 60 rpm. Samples were taken after the first, third, fifth and seventh extrusion cycles and their tensile properties and morphology were determined. Scanning electron microscopy indicated that two phases were observed in the blend which showed spherical PHB domains. The addition of clay, PP-g-MA and erucamide improved the adhesion between the nanocomposites components. X-ray diffraction analysis showed that crystallinity tended to increase with the number of reprocessing cycles for all systems investigated up to the fifth cycle and then tended to decrease. A 10% crystallinity increase was observed for neat PP in the fifth cycle. In general, the tensile properties of all systems decreased with reprocessing and the highest losses were observed for the PP/PHB blend after seven processing cycles with 50% and 37% decreases in stress at break and elastic modulus, respectively. Impact strength of the PP matrix and of the PP/PHB blend tended to decrease with reprocessing, except for the nanocomposite which showed a slight increase especially after the seventh processing cycle in which an 18% increase in impact strength was observed. (author)
Primary Subject
Source
Available from: https://www.scielo.br/j/mr/a/ZYr83j5M9cMJgMtrR9GdCZh/?format=pdf& lang=en
Record Type
Journal Article
Journal
Materials Research (Sao Carlos, Online); ISSN 1980-5373; ; v. 24(4); 11 p
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
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