Papers by Edson Noriyuki Ito
Clay Minerals, 2016
The use of Mg-montmorillonite in the production of organoclay without sodium activation was inves... more The use of Mg-montmorillonite in the production of organoclay without sodium activation was investigated. For this purpose, organophilization experiments were carried out by varying the concentration of two surfactants: hexadecyltrimethylammonium (HDTMA+) and dodecyltrimethylammonium (DTMA+) ions. These surfactantswere used at concentrations 0.7, 1.0 and 1.5 times that of the cation exchange capacity (62.6 meq/100 g) of the clay, with a reaction time of 8 h at temperatures of 25 and 80°C. X-ray diffraction (XRD) results confirmed the intercalation for bothin naturaand activated samples. The Fourier-transforminfrared (FTIR) spectroscopy and XRD results showed that the ratio ofgauche/transconformers decreased with increased basal spacing. The results of thermodifferential and thermogravimetric analysis (DTA/DTG) confirmed the thermal stability of the organoclay up to 200°C, permitting the use of suchmaterial in the synthesis of polymer/clay nanocomposites obtained by the melt blending...
Todos os direitos reservados. A reprodução não-autorizada desta publicação, no todo ou em parte, ... more Todos os direitos reservados. A reprodução não-autorizada desta publicação, no todo ou em parte, o constitui violação dos direitos autorais (Lei n 9.610). CIP-Brasil. Catalogação-na-publicação. Embrapa Instrumentação Agropecuária
Macromolecular Symposia
The aim of this study is to evaluate toughness mechanism of elastomeric poly(methyl methacrylate)... more The aim of this study is to evaluate toughness mechanism of elastomeric poly(methyl methacrylate) (PMMAe) and polycarbonate (PC) blend through crack propagation at high speed tensile tests. Samples are processed using two types of extruders, single and twin screw, in order to eliminate the influence of processing in the final product's properties. Pure polymers and polymer blend samples are cryo‐ultramicrotomed and their morphology is characterized using atomic force microscopy (AFM). Fractured samples obtained from uniaxial tensile tests at high strain rate are inspected using optical microscopy (OM) and scanning electron microscopy (SEM). The results obtained for the PMMAe/PC blend in tests at high deformation rate showed that the shear rate during the mixing process influences the maximum strength of the polymer blend near its region of co‐continuous morphology. The visual evaluation of the fracture surface and the fractographic analysis corroborated the results of this study...
EnglishAn short overview is presented on properties of nanocomposites of Poly(methyl methacrylate... more EnglishAn short overview is presented on properties of nanocomposites of Poly(methyl methacrylate), PMMA, with organically montmorillonite (MMT) modified clays synthesized by in situ polymerization assisted by sonication. The results for various methods of polymerization were compared and discussed, as well the process with and without sonication. The structural characterization and thermal and mechanical properties were considered. It was observed a lack of a systematic approach to study the in situ polymerization of PMMA/organoclays nanocomposites, as statistically designed experiments. Therefore, it was proposed a central composing design (CCD) with two factors: (1) Energy of sonication and (2) Flory–Huggins interaction parameter between PMMA and nanoclay. portuguesE apresentada uma breve revisao sobre asintese e propriedades de nanocompositos de polimetacrilato de metila (PMMA) com argilas montmorillonitas (MMT) organicamente modificadas via polimerizacao in situ assistida com a...
Journal of Materials Research and Technology, 2020
This work evaluated the effects of cold plasma treatment on kapok fibers (Ceiba pentandra L.). Fo... more This work evaluated the effects of cold plasma treatment on kapok fibers (Ceiba pentandra L.). Fourier-transform infrared (FTIR) spectra showed changes in characteristic absorption bands, indicating modification of the chemical composition of the fiber. Surface roughness, observed by field-emission gun scanning electron microscope (FEG-SEM), increased. Furthermore, the water uptake was significantly affected, the ability to uptake oil increased and a mechanism of reaction was suggested. The thermal behavior, analyzed by thermogravimetric analysis (TGA), was slightly altered and it was also shown that fiber surface was activated by the plasma treatment. Ultimately, cold plasma may prove as a feasible approach to improve fiber-matrix adhesion for the production of biodegradable polymer composites.
Polymer Testing, 2018
The effect of the type of filler and concentration on the degradation rate of compounds based on ... more The effect of the type of filler and concentration on the degradation rate of compounds based on a blend of poly (β-hydroxybutyrate) (PHB) and poly (butylene adipate-co-terephthalate) (PBAT) were studied using a fast and simple procedure of monitoring polymer degradation under processing conditions using torque rheometry. It was found that both the presence and level of two types of filler, taken from two different layers of the babassu palm fruit (mesocarp and epicarp), greatly increase incipient degradation of the blend when processed in an internal laboratory mixer. The qualitative trends and quantitative estimates may be explained by the chemical and morphological characteristics of the two fillers, as observed by optical microscopy. Fracture surface morphology was investigated by scanning electron microscopy (SEM) and indicated better filler-matrix adhesion in PHB-rich blends in epicarp compounds.
Cellulose, 2019
Abstract In this study, composites from recycled polyethylene and kapok fibers were prepared with... more Abstract In this study, composites from recycled polyethylene and kapok fibers were prepared with fiber contents of 1, 5 and 10 wt%. Cold plasma treatment was applied to the fibers in an attempt to improve fiber/matrix adhesion. The characterization of plasma treated fibers indicated modification in chemical composition and water and oil uptake, as compared to untreated fibers. The addition of plasma treated fibers to the polymer promoted a reduction in the steady-state torque during mixing. In addition, the thermal conductivity of composites was reduced as the amount of fibers increased. Dynamic mechanical thermal analyses of composites with plasma-treated fibers indicated an increase in storage moduli, as well as an increase in glass transition temperature as compared to the pure polymer. Images of fractured surfaces show fibers well connected to the matrix suggesting good fiber/matrix adhesion. Thus, cold plasma is demonstrated as a viable non-polluting alternative to activate cellulosic fibers and improve fiber/matrix interface in polymer composites. Graphic abstract
Composite Interfaces, 2018
Composites from recycled polyethylene and kapok fibers were prepared using untreated and plasma-t... more Composites from recycled polyethylene and kapok fibers were prepared using untreated and plasma-treated fibers. Flow properties, mechanical properties and fracture morphology were analyzed in order to evaluate the effects of cold plasma treatment on kapok fibers to improve interfacial bonding between fibers and matrix. Melt flow rate (MFR) measurements indicated a reduction in flow rate of the polymer with the addition of kapok fibers. Storage modulus increased with fiber addition and this effect was more significant when plasmatreated fibers were used. Tanδ obtained from viscoelastic characterization also suggested improvements in fiber/matrix interface as a result of plasma treatment. Addition of kapok fibers to polyethylene produced a reduction in onset decomposition temperature determined from thermogravimetry curve. However, the decrease in temperature observed does not limit composite processing. Furthermore, the degree of crystallinity of polyethylene increased with the addition of untreated fibers and reduced when plasma treated fibers were added. Morphological analysis of failure surface by Field Emission Gun Scanning Electron Microscopy (FEGSEM) suggest that fiber/matrix adhesion was clearly improved when plasma treated fibers were used. Thus, the oxygen cold plasma treatment proved to be an effective non-polluting approach to enhance matrix/fiber adhesion in polyethylene/kapok fiber composites, as opposed to chemical treatments.
Composite Interfaces, 2017
This work is aimed at the one-step chemical modification of the surface of cashew wood flour part... more This work is aimed at the one-step chemical modification of the surface of cashew wood flour particles using the technical grade cashew nut shell liquid (CNSL). The goal is to develop an alternative way to introduce chemically active sites on the surface of the particles, which allows the addition of new functionalities to such particles. The influence of time and temperature and catalyst on the substitution of lignocellulosic hydroxyls with cardanol/cardol urethane derivatives was evaluated by thermogravimetric analysis, scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and contact angle measurements. The mechanical behavior of the modified particles in polypropylene composites was also evaluated by mechanical testing and dynamic mechanical thermal analysis. The FTIR, thermogravimetry, and contact angle results indicated changes on the particle surface, and the mechanical and thermomechanical behavior of the mercerized and modified particles in the composites was found to be similar. These results point that the CNSL approach is a viable way to chemically modify cashew wood flour particle surfaces, while maintaining their properties.
Dyes and Pigments, 2017
Polymer modification has been used as a means to improve the adhesion/bonding of compounds and/or... more Polymer modification has been used as a means to improve the adhesion/bonding of compounds and/or particles to polymer chains, but this goal is not always achieved. Some compounds contain naturally reactive groups which, in contact with the polymer, can modify its properties. This work focused on the rheological (torque and parallel plates rheometry) and mechanical (tensile and impact) characterization of PMMA containing the DV31, DBL3 and DB79 aminic dyes and the DR73 inert dye. The rheological results indicated that the final torque (torque rheometry) varied in response to increasing dye concentrations, and that the various dyes under study exhibited distinct behaviors (parallel plates rheometry). The mechanical tests revealed that, overall, the effect of the dyes on the properties of PMMA was negligible, except for DV31, that led to the decrease in the impact strength, possibly due to the bond between chains or segments of chains of the polymer. The presence, amount and type of amine in the dyes gave rise to significant rheological changes in PMMA because of the reactivity between the amine and the ether group of PMMA.
Resumo: Uma blenda de polietileno de alta densidade e polietileno de baixa densidade linear (PEAD... more Resumo: Uma blenda de polietileno de alta densidade e polietileno de baixa densidade linear (PEAD/PEBDL) comumente utilizada em filmes de embalagem foi modificada com argila montmorilonita organofílica comercial visando à obtenção de nanocompósitos com melhores propriedades barreira. Filmes produzidos com o nanocompósito foram avaliados quanto à permeabilidade ao oxigênio e ao vapor d'água. Amostras com 5 e 7,5% de argila (em massa) foram estudadas em diferentes condições de processamento. As propriedades mecânicas também foram determinadas. O modelo de Nielsen foi aplicado e demonstrou ser um ótimo recurso para avaliação do grau de esfoliação das argilas por meio da avaliação do nível de esfoliação da argila para as diferentes amostras, que foram confirmadas pelas análises realizadas em microscopia eletrônica de transmissão. Palavras-chave: nanocompósitos, montmorilonita, propriedades barreira, blendas poliméricas Application of Nielsen´s model to HDPE/LLDPE nanocomposites for ...
Express Polymer Letters, 2010
The use of natural fibers as reinforcement for LDPE in extrusion of thin plates, can generate goo... more The use of natural fibers as reinforcement for LDPE in extrusion of thin plates, can generate good studies of applications. In this work we evaluate the thermal, mechanical and morphological properties of LDPE with 10% w/w of CF and addition of the maleic anhydride functionalized PE (PE-g-MAH). PEg -MAH was used as compatibiliser agent to provide better adhesion between the LDPE and the CF. Thermal analysis behaviour was using to helping to establish the processing temperatures, the morphological studies were conducted to evaluate the interfacial adhesion. The CF maintained and enhanced the level of mechanical properties and improved the surface appearance.
LWT - Food Science and Technology, 2015
Polysaccharides have been used in several studies to form films and coatings to be used as packag... more Polysaccharides have been used in several studies to form films and coatings to be used as packaging materials (or to complement packaging materials) for foods. The incorporation of nanofillers such as montmorillonite (MMT) has been suggested to improve the barrier and mechanical properties of biomaterials. Films from starch and cashew tree gum (CTG) were developed according to a central composite design with two variables: MMT concentration and sonication time. MMT concentrations of 5e10 g/100 g increased tensile strength and elastic modulus, while higher MMT concentrations impaired those properties. The moisture barrier has been favored by MMT, while transparency and elongation have been impaired by the nanofiller. Sonication favored strength and modulus, probably because of a better MMT dispersion. Starch-CTG coatings with or without MMT were applied to cashew nut kernels. Coated kernels presented reduced moisture absorption during 120 days of storage (especially those coated with the nanocomposite coating), indicating that the coatings could decrease the texture changes of kernels. Moreover, the oxidation rates during storage were similarly decreased by both coatings.
Journal of Thermal Analysis and Calorimetry, 2013
High-density polyethylene/modified bentonite clay/polar compatibilizer nanocomposites were prepar... more High-density polyethylene/modified bentonite clay/polar compatibilizer nanocomposites were prepared through the melt intercalation process. The clay was organophilizated using different percentages of quaternary ammonium salt 100, 125, and 150 % based cation exchange capacity of the clay. The nanocomposites were prepared in a counter-rotating twin-screw extruder and then specimens were injection molded. For the evaluation of flammability of the test system was used for burning in the horizontal position according to the norm (Underwriters Laboratories, UL94HB) and to the method of cone calorimeter. The thermal behavior of nanocomposites was evaluated by thermogravimetry and X-ray diffraction techniques, and transmission electron microscopy were used to characterize the morphology and analyze the degree of expansion of the clays prepared and the degree of exfoliation of nanocomposites. It was observed that the percentage of ammonium salt and the compatibilizer polar influence on the final properties of the systems and consequently improving the thermal stability and reducing the flammability of the matrix.
Journal of Biobased Materials and Bioenergy, 2008
Page 1. Delivered by Ingenta to: ? IP : 93.91.26.12 Sat, 04 Dec 2010 10:54:38 RESEARCH AR TICLE C... more Page 1. Delivered by Ingenta to: ? IP : 93.91.26.12 Sat, 04 Dec 2010 10:54:38 RESEARCH AR TICLE Copyright © 2008 American Scientific Publishers All rights reserved Printed in the United States of America Journal of Biobased Materials and Bioenergy Vol. 2, 231242, 2008 ...
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Papers by Edson Noriyuki Ito