In contrast to the traditional fillers, clay, in particular, natural smectite clay represents an environmentally significant alternative to improve the properties of polymers. Compared to con-ventional nanofillers, smectite clay can... more
In contrast to the traditional fillers, clay, in particular, natural smectite clay represents an environmentally significant alternative to improve the properties of polymers. Compared to con-ventional nanofillers, smectite clay can effectively enhance the physical and mechanical properties of polymer nanocomposites with a relatively small amount of addition (< 5 wt%). The present study focuses on investigating the reinforcing efficiency of different amounts (up to 5 wt%) of a natural Brazilian smectite clay on the mechanical and thermal properties of poly(butylene terephthalate) (PBT) nanocomposites. Natural Brazilian clay modified by addition of quaternary salt and sodium carbonate (MBClay) was infused into the PBT polymer by melt extrusion, using a twin-screw extruder. It was found that the best properties for PBT were obtained at 3.7 wt% of modified BClay. Tensile strength at break exhibited an increase of about 60 %, flexural strength increased by 24 % and flexural modulus i...
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Poly [(ethylene)-co-(vinyl acetate)] (EVA) is a thermoplastic copolymer composed of randomly distributed polyethylene and polyvinyl acetate sequences within the molecular chain. EVA combines toughness with excellent flexibility, impact... more
Poly [(ethylene)-co-(vinyl acetate)] (EVA) is a thermoplastic copolymer composed of randomly distributed polyethylene and polyvinyl acetate sequences within the molecular chain. EVA combines toughness with excellent flexibility, impact and puncture resistance. Because of these properties, this material is largely used for foam production as padding in equipment for various sports and as a shock absorber in sport’s shoes. This work aims to study the influence of clay reinforcement on the performance of recycled polymer foams. The blend containing recycled HDPE (high density polyethylene) and recycled EVA (70/30 wt%, respectively) reinforced with 2 wt% of clays were prepared by melt extrusion, using a twin-screw extruder to obtain the composites. The composites and foaming agent were fed into a special single screw extruder for foaming. The samples of HDPE/EVA/Clay foams were characterized by tensile test, Field Emission Scanning Electron Microscopy (FE-SEM), Thermogravimetric Analysi...
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Treatment with ionizing radiation, particularly, electron-beam radiation is a promising approach to the controllable modification of the properties of polymeric flexible packaging materials, in order to adjust their physicochemical,... more
Treatment with ionizing radiation, particularly, electron-beam radiation is a promising approach to the controllable modification of the properties of polymeric flexible packaging materials, in order to adjust their physicochemical, mechanical, optical, barrier and other properties. In recent years, electron-beam radiation has been efficiently applied in the flexible packaging industry to promote cross-linking and scission of the polymeric chains to improve specific material mechanical properties. On the other hand, ionizing radiation can also affect the polymeric material itself leading to a production of free radicals. These free radicals can in turn lead to degradation and or cross-linking phenomena, with release of gases, discoloration, changes in mechanical, thermal and barrier properties, degradation and leaching of polymer additives into solvents [4, 7]. The use of the multilayer laminated or coextruded structures of flexible packaging is rising in food packaging industries b...
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In the present work, the changes in physicochemical, morphological and thermal properties of HDPE/Piassava fiber/nanoclay and HDPE/Piassava fiber/nanoclay/PP blend electron-beam irradiated were evaluated. The samples were irradiated with... more
In the present work, the changes in physicochemical, morphological and thermal properties of HDPE/Piassava fiber/nanoclay and HDPE/Piassava fiber/nanoclay/PP blend electron-beam irradiated were evaluated. The samples were irradiated with 100 kGy using a 1.5 MeV electron beam accelerator, at room temperature, in presence of air. The irradiated and non-irradiated samples were submitted to thermo-mechanical tests, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and the correlation between their properties was discussed. The results showed that the incorporation of Piassava (Attalea funifera Mart) fiber and nanoclay followed by electron-beam irradiation represented a significant gain (p < 0.05) in thermo-mechanical properties, changes in surface morphology and reduction in MFI. After irradiation, the nanocomposite showed a gain in the degree of cross-linking, and a better interfacial adhesion between fiber, nanoclay and HDPE. In addition, the HDPE/Piassava fiber/...
In the present work, the changes in physicochemical, morphological and thermal properties of electron-beam irradiated ethylene–vinyl alcohol copolymer (EVOH) resin and EVOH resin reinforced with piassava (Attalea funifera Mart) fiber, as... more
In the present work, the changes in physicochemical, morphological and thermal properties of electron-beam irradiated ethylene–vinyl alcohol copolymer (EVOH) resin and EVOH resin reinforced with piassava (Attalea funifera Mart) fiber, as a function of radiation dose, were investigated. The materials were irradiated up to 90 kGy using a 1.5 MeV electron beam accelerator, at room temperature in presence of air. The changes in properties of the EVOH and of the reinforced EVOH, after irradiation, were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and sol-gel analysis. The correlation between the properties of the EVOH and of the EVOH-piassava, both irradiated and non-irradiated samples, were discussed. The results showed that there were no significant differences (p < 0.05) in the enthalpy, crystallinity percentage variation and initial degradation temperature of the non-irradiated and irradiated EVOH....
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ABSTRACT Natural cellulose-based fibers offer low cost, low density composite reinforcement with good strength and stiffness. Because of their annual renewability and biodegradability, natural fibers have materialized as... more
ABSTRACT Natural cellulose-based fibers offer low cost, low density composite reinforcement with good strength and stiffness. Because of their annual renewability and biodegradability, natural fibers have materialized as environmentally-friendly alternatives to synthetic fibers in the last two decades. They are replacing synthetic materials in some traditional composites in industrial manufacturing sectors such as automotive, construction, furniture, and other consumer goods. In this work, the use of lignocellulosic fibers in green materials engineering, particularly their application as polymeric composite reinforcement and surface treatment via ionizing radiation are reviewed. Because these cellulose-based materials are intrinsically hydrophilic, they require surface modification to improve their affinity for hydrophobic polymeric matrices, which enhances the strength, durability, and service lifetime of the resulting lignocellulosic fiber-polymer composites. In spite of a long history of using chemical methods in the modification of material surfaces, including the surface of lignocellulosic fibers, recent research leans instead towards application of ionizing radiation. Ionizing radiation methods are considered superior to chemical methods, as they are viewed as clean, energy saving, and environmentally friendly. Recent applications of controlled ionizing radiation doses in the formulation of natural fiber –reinforced polymeric composites resulted in products with enhanced fiber-polymer interfacial bonding without affecting the inner structure of lignocellulosic fibers. These applications are critically reviewed in this contribution.
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This work evaluates the effects of carbon black incorporation on morphological, mechanical and thermal properties of biodegradable films. The biodegradable composite films based on PBAT/PLA blend and PBAT/PLA blend containing 2 wt. % of... more
This work evaluates the effects of carbon black incorporation on morphological, mechanical and thermal properties of biodegradable films. The biodegradable composite films based on PBAT/PLA blend and PBAT/PLA blend containing 2 wt. % of carbon black were prepared by melt extrusion, using a twin screw extruder machine and blown extrusion process. The properties of biodegradable film samples were investigated by tensile tests, XRD, MFI, TGA, DSC and FE-SEM analysis and the correlation between properties was discussed.
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Currently, ethylene vinyl alcohol (EVOH) is one of the oxygen barrier materials most used for food packaging. The addition of graphene oxide nanosheets to the EVOH matrix is employed to improve their mechanic al and barrier properties. In... more
Currently, ethylene vinyl alcohol (EVOH) is one of the oxygen barrier materials most used for food packaging. The addition of graphene oxide nanosheets to the EVOH matrix is employed to improve their mechanic al and barrier properties. In this work, films of EVOH-based composites reinforced with graphene oxide were prepared by melt extrusion, using a twin screw extruder machine and blown extrusion process. The graphene oxide was prepared via chemical oxidation of natural graphite and then was exfoliated into nanosheets using the sonochemical method. The composite films samples were characterized using FTIR and DSC analysis. In addition, their mechanical properties were also determined.
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The use of natural fibers with polymeric resins has spread rapidly. In order to improve the mechanical properties of material, in this work, two variables were used: mercerization and electron beam irradiation. This paper describes the... more
The use of natural fibers with polymeric resins has spread rapidly. In order to improve the mechanical properties of material, in this work, two variables were used: mercerization and electron beam irradiation. This paper describes the preparation and characterization of bio-composites that were prepared in two different routes using green high density polyethylene (HDPE) and Brazil nut pod fiber (BNPF): the first was to irradiate the composite with 150 kGy and the second was to irradiate the matrix with 15 kGy followed by composite preparation. In both cases mercerized and non-mercerized fibers were used. The irradiation process was carried out using a 1.5 MeV electron beam accelerator, at room temperature and in the presence of air. The material was characterized to evaluate the effect of treatment on mechanical properties of material.
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The composite is an alternative favorable for different industries because they combine the best mechanical properties with the best physic-chemistry properties of two or more materials. Environmental issues are forcing industry to seek... more
The composite is an alternative favorable for different industries because they combine the best mechanical properties with the best physic-chemistry properties of two or more materials. Environmental issues are forcing industry to seek alternative, more eco-friendly materials; using natural fibers with polymers based on renewable resources will allow many environmental issues to be solved. In this sense, researches with focus on vegetal fibers as reinforcement in composites is growing and positive results in performance have been achieved. This paper describes the preparation and characterization of bio-composite that was developed from Brazil Nut Shell Fiber (BNSF) and green high-density polyethylene (HDPE G). The composite prepared was irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator, at room temperature, in presence of air. The samples were characterized to understand the nature of interaction between BNSF reinforcement and HDPE matrix and their properties were discussed.
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The plastics are present in most of the materials used and are generally discarded quickly, which makes necessary the development of sustainable materials. The issue of sustainability has been worldwide high, encouraging the development... more
The plastics are present in most of the materials used and are generally discarded quickly, which makes necessary the development of sustainable materials. The issue of sustainability has been worldwide high, encouraging the development of sustainable alternatives thus aiming to preserve resources for future generations. Thus, in recent years, the synthesis of potentially biodegradable polymers is of considerable significance and has receiving much attention. However, the mechanical properties of biodegradable polymers are very poor for many applications. In this work, copolyester/starch blend reinforced with rice husk ash was prepared by melt-mixing processing, using a twin screw extruder machine. The composite samples were submitted to tensile and impact tests, SEM and XRD analysis, and the correlation between their properties were discussed.
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Research Interests: Chemical Engineering, Materials Science, Radiation Physics, Nanomaterials, Polymer Nanocomposites, and 13 morePolymer Composites, Polyethylene, Polypropylene, Composite Material, Dose rate, Radiation Dose, Room Temperature, Irradiation, Poly (Ethylene Terephthalate), Electron Beam, Tensile Strength, Electron beam irradiation, and Mechanical Property
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The aim of this work is obtaining and characterization of polypropylene nanocomposites based on organophilic clay and used bond paper. A Brazilian polycationic bentonite was treated with sodium carbonate to transform it into a swelling... more
The aim of this work is obtaining and characterization of polypropylene nanocomposites based on organophilic clay and used bond paper. A Brazilian polycationic bentonite was treated with sodium carbonate to transform it into a swelling bentonite and then treated with ammonium hexadecyltrimethyl ammonium chloride to turn it into an organoclay, swelling in organic liquids. The mixture, with 1% by weight of organophilic clay and paper powder, with 1% by weight, was processed using a twin-screw extruder. The nanocomposites were compatibilized with 2% by weight of polypropylene graft (PP-g-AM). The materials were evaluated for their mechanical properties and morphology, by tests such as XRD, SEM, FTIR, DSC. The nanocomposites showed improved mechanical properties compared with the polymer without filler.
Packaging materials have been widely processed by ionizing radiation in order to improve their chemical and physical properties and also for sterilization purposes. Basically, flexible packaging manufacturers apply specific radiation... more
Packaging materials have been widely processed by ionizing radiation in order to improve their chemical and physical properties and also for sterilization purposes. Basically, flexible packaging manufacturers apply specific radiation doses to promote cross-linking and scission of the polymeric chains and thus obtain alterations in certain properties of the material. While enhancing a specific property, significant losses may result in others. In this study, we examined the effects of E-beam radiation on a commercial multilayer PA6/LDPE based film, irradiated with doses up to 127 kGy. Food producers mostly use this structure as a thermoforming bottom web for processed meat products. Two weeks after irradiation, tensile strength and elongation of the film were analyzed. Both mechanical properties were again analyzed 18 months after irradiation took place. Significant changes of mechanical properties were observed specially 18 months after irradiation. Once cross-linking and scission a...
RESUMO Neste trabalho o polietileno de alta densidade (HDPE) foi submetido às doses de radiação de 150 à 250 kGy em um acelerador de elétrons de 1,5 MeV com o propósito de avaliar o efeito da dose de radiação nas suas propriedades... more
RESUMO Neste trabalho o polietileno de alta densidade (HDPE) foi submetido às doses de radiação de 150 à 250 kGy em um acelerador de elétrons de 1,5 MeV com o propósito de avaliar o efeito da dose de radiação nas suas propriedades mecânicas. As irradiações foram realizadas à taxa de dose de 14 kGy/s, temperatura ambiente e presença de ar. As mudanças causadas pela irradiação nas propriedades mecânicas do material foram avaliadas por meio dos ensaios de resistência à tração e à flexão. Os resultados mostraram um ganho de até 150 % na resistência à tração na ruptura original do HDPE (amostras não irradiadas), ganho de até 10 % na porcentagem de elongação máxima na ruptura para as amostras irradiadas, exceto para a dose de 250 kGy, onde não foram observadas mudanças significativas (p < 0,05). Os resultados mostram também ganhos de até 20 % na resistência à flexão e perdas da ordem de 3 à 4 % na resistência à tração no escoamento do HDPE em relação à original para o intervalo de dose...
ABSTRACT This work presents the preparation and characterization of a nanocomposite based on Poly(butylene terephthalate) PBT and Brazilian smectitic clay (bentonite chocolate clay). Before being incorporated as clay nanoparticles in PBT... more
ABSTRACT This work presents the preparation and characterization of a nanocomposite based on Poly(butylene terephthalate) PBT and Brazilian smectitic clay (bentonite chocolate clay). Before being incorporated as clay nanoparticles in PBT resin, the clay was organically modified by the addition of a quaternary salt and sodium carbonate. PBT/Clay nanocomposite (96.3:3.70 wt %) was obtained by using a twin-screw extruder machine. After extrusion process, the nanocomposite was characterized by tensile, flexural and impact tests, SEM, Vicat, HDT, DSC, TGA and XRD tests. The results showed that the properties of the nanocomposite obtained were superior to those of neat PBT. Concerning the temperature of thermal distortion (HDT) an expressive gain of around 45% was presented to PBT/Clay nanocomposite compared to PBT evidencing the interaction of nanofiller with the polymeric matrix.
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TFE is highly unstable. It can easily go through an explosive disproportionation reaction under polymerization. The present work proposes the use of ionizing radiation for the study of monomer stability by inducing the polymerization and... more
TFE is highly unstable. It can easily go through an explosive disproportionation reaction under polymerization. The present work proposes the use of ionizing radiation for the study of monomer stability by inducing the polymerization and disproportionation reactions. Radiation was used to promote the initiation of TFE polymerization with and without inhibitors. Inhibitors and TFE were irradiated by γ-rays from 60Co.
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In the present work, the morphological, thermal and viscoelastic behavior of high density polyethylene (HDPE) matrix composites were investigated. HDPE reinforced with the piassava fiber weight fractions varying to 10% to 40% were... more
In the present work, the morphological, thermal and viscoelastic behavior of high density polyethylene (HDPE) matrix composites were investigated. HDPE reinforced with the piassava fiber weight fractions varying to 10% to 40% were prepared an characterized by ...
Page 1. 2009 International Nuclear Atlantic Conference - INAC 2009 Rio de Janeiro,RJ, Brazil, September27 to October 2, 2009 ASSOCIAÇÃO BRASILEIRA DE ENERGIA NUCLEAR - ABEN ISBN: 978-85-99141-03-8 EVALUATION ...
The influence of electron-beam irradiation on mechanical properties of commercial multilayer flexible packaging materials based on coextruded and laminated polypropylene (PP) ,low-density polyethylene (LDPE), ethylene vinyl alcohol... more
The influence of electron-beam irradiation on mechanical properties of commercial multilayer flexible packaging materials based on coextruded and laminated polypropylene (PP) ,low-density polyethylene (LDPE), ethylene vinyl alcohol copolymer (EVOH) and poly (ethylene terephthalate) (PET), irradiated with doses up to 120 kGy, was studied. The tensile strength and elongation at break of the irradiated
PET/PP film increase, while the penetration and sealing resistance decreased. In addition, the irradiated PET/LDPE/EVOH/LDPE film presented increase in the tensile strength on some radiation doses and decrease of the penetration and sealing resistance, except for sealing resistance atradiation dose of 15kGy that resulted in as light increase of ca 4%.
PET/PP film increase, while the penetration and sealing resistance decreased. In addition, the irradiated PET/LDPE/EVOH/LDPE film presented increase in the tensile strength on some radiation doses and decrease of the penetration and sealing resistance, except for sealing resistance atradiation dose of 15kGy that resulted in as light increase of ca 4%.
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Compositesofacrylamide,glycerin,gelatinandBrazilnutsshellfiberhavebeenpreparedbythe solution/suspensioncastingtechnique.Theeffectoftwodosesofelectronbeam(EB)irradiationonthe... more
Compositesofacrylamide,glycerin,gelatinandBrazilnutsshellfiberhavebeenpreparedbythe
solution/suspensioncastingtechnique.Theeffectoftwodosesofelectronbeam(EB)irradiationonthe
structuralpropertiesofthepolymericcompositeshasbeeninvestigatedbyX-raydiffraction,thermo-
gravimetricanalysis(TG),scanningelectronmicroscope(SEM),gelcontentandtheswellingbehavior.
Gel contentincreasedwiththeradiationdose.TheresultsobtainedbyX-raydiffractionanalysissuggest
that crystallinitydecreaseswithincreasingdose.Thegelatin/fibercomposites,beforeandafter
irradiation,showedtobepoorlystableagainstthermaldecomposition.
solution/suspensioncastingtechnique.Theeffectoftwodosesofelectronbeam(EB)irradiationonthe
structuralpropertiesofthepolymericcompositeshasbeeninvestigatedbyX-raydiffraction,thermo-
gravimetricanalysis(TG),scanningelectronmicroscope(SEM),gelcontentandtheswellingbehavior.
Gel contentincreasedwiththeradiationdose.TheresultsobtainedbyX-raydiffractionanalysissuggest
that crystallinitydecreaseswithincreasingdose.Thegelatin/fibercomposites,beforeandafter
irradiation,showedtobepoorlystableagainstthermaldecomposition.
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The plastics are present in most of the materials used and are generally discarded quickly, which makes necessary the development of sustainable materials. The issue of sustainability has been worldwide high, encouraging the development... more
The plastics are present in most of the materials used and are generally discarded quickly, which
makes necessary the development of sustainable materials. The issue of sustainability has been
worldwide high, encouraging the development of sustainable alternatives thus aiming to preserve
resources for future generations. Thus, in recent years, the synthesis of potentially biodegradable
polymers is of considerable significance and has receiving much attention. However, the
mechanical properties of biodegradable polymers are very poor for many applications. In this
work, copolyester/starch blend reinforced with rice husk ash was prepared by melt-mixing
processing, using a twin screw extruder machine. The composite samples were submitted to
tensile and impact tests, SEM and XRD analysis, and the correlation between their properties
were discussed.
makes necessary the development of sustainable materials. The issue of sustainability has been
worldwide high, encouraging the development of sustainable alternatives thus aiming to preserve
resources for future generations. Thus, in recent years, the synthesis of potentially biodegradable
polymers is of considerable significance and has receiving much attention. However, the
mechanical properties of biodegradable polymers are very poor for many applications. In this
work, copolyester/starch blend reinforced with rice husk ash was prepared by melt-mixing
processing, using a twin screw extruder machine. The composite samples were submitted to
tensile and impact tests, SEM and XRD analysis, and the correlation between their properties
were discussed.
Research Interests:
The composite is an alternative favorable for different industries because they combine the best mechanical properties with the best physic-chemistry properties of two or more materials. Environmental issues are forcing industry to seek... more
The composite is an alternative favorable for different industries because they combine the best
mechanical properties with the best physic-chemistry properties of two or more materials.
Environmental issues are forcing industry to seek alternative, more eco-friendly materials; using
natural fibers with polymers based on renewable resources will allow many environmental issues
to be solved. In this sense, researches with focus on vegetal fibers as reinforcement in
composites is growing and positive results in performance have been achieved. This paper
describes the preparation and characterization of bio-composite that was developed from Brazil
Nut Shell Fiber (BNSF) and green high-density polyethylene (HDPE G). The composite
prepared was irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator, at
room temperature, in presence of air. The samples were characterized to understand the nature of
interaction between BNSF reinforcement and HDPE matrix and their properties were discussed.
mechanical properties with the best physic-chemistry properties of two or more materials.
Environmental issues are forcing industry to seek alternative, more eco-friendly materials; using
natural fibers with polymers based on renewable resources will allow many environmental issues
to be solved. In this sense, researches with focus on vegetal fibers as reinforcement in
composites is growing and positive results in performance have been achieved. This paper
describes the preparation and characterization of bio-composite that was developed from Brazil
Nut Shell Fiber (BNSF) and green high-density polyethylene (HDPE G). The composite
prepared was irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator, at
room temperature, in presence of air. The samples were characterized to understand the nature of
interaction between BNSF reinforcement and HDPE matrix and their properties were discussed.
Research Interests:
Natural fibers, mainly those lignocellulosic extracted from plants, have, in the past few decades, attracted the attention not only of scientists but also of industrial technologists of our society interested in their engineering... more
Natural fibers, mainly those lignocellulosic extracted from plants, have, in the past few decades, attracted the
attention not only of scientists but also of industrial technologists of our society interested in their
engineering materials. As it is well known, uses of natural fiber in clothes carpets, baskets, ropes and low
cost construction roofing has existed from the beginning of our civilization. Today environmental and energy
saving issues are motivating research works on new uses of lignocellulosic fibers in polymer composites.
Moreover, industrial application of lignocellulosic fiber composites are already in technological sectors such
the automobile industry, packing and civil construction. In addition to environmental, economical and social
benefits, some lignocellulosic fibers present specific properties that are not comparable to those of other
synthetic fiber used for polymer composite reinforcement. In fact, the mechanical strength and stiffness of
any natural fibers is, however, significantly inferior and needs to be improved in order to compete with those
of the synthetic fibers. The present work investigated the effect of electron beam irradiation on the
mechanical behavior of the buriti petiole fiber, which presents a potential for composite reinforcement.
Distinct lots of buriti fibers were irradiated at 50, 250 and 500 kGy using a 1.5 MeV electron beam
accelerator. The results showed marked changes in the tensile properties of the buriti petiole fiber. This was
discussed in terms of the structural modifications occurring in the irradiated lignocellulosic structure.
attention not only of scientists but also of industrial technologists of our society interested in their
engineering materials. As it is well known, uses of natural fiber in clothes carpets, baskets, ropes and low
cost construction roofing has existed from the beginning of our civilization. Today environmental and energy
saving issues are motivating research works on new uses of lignocellulosic fibers in polymer composites.
Moreover, industrial application of lignocellulosic fiber composites are already in technological sectors such
the automobile industry, packing and civil construction. In addition to environmental, economical and social
benefits, some lignocellulosic fibers present specific properties that are not comparable to those of other
synthetic fiber used for polymer composite reinforcement. In fact, the mechanical strength and stiffness of
any natural fibers is, however, significantly inferior and needs to be improved in order to compete with those
of the synthetic fibers. The present work investigated the effect of electron beam irradiation on the
mechanical behavior of the buriti petiole fiber, which presents a potential for composite reinforcement.
Distinct lots of buriti fibers were irradiated at 50, 250 and 500 kGy using a 1.5 MeV electron beam
accelerator. The results showed marked changes in the tensile properties of the buriti petiole fiber. This was
discussed in terms of the structural modifications occurring in the irradiated lignocellulosic structure.
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tThe effects of electron-beam radiation treatment on fiber-matrix adhesion and mechanical propertiesof short piassava fibers reinforced high density polyethylene (HDPE) matrix were studied. Glycidylmethacrylate (GMA) was added at 2.5% and... more
tThe effects of electron-beam radiation treatment on fiber-matrix adhesion and mechanical propertiesof short piassava fibers reinforced high density polyethylene (HDPE) matrix were studied. Glycidylmethacrylate (GMA) was added at 2.5% and 5.0% (on piassava fiber wt) as a cross-linking agent andthe effects upon the properties of the resulting composites treated by electron-beam radiation werealso examined. HDPE reinforced with short piassava fiber composites was prepared by melt-mixingprocessing, using a twin screw extruder machine. The materials were irradiated with 100 and 200 kGyusing a 1.5 MeV electron beam accelerator, at room temperature in presence of air. Material samples weresubmitted to mechanical and thermo-mechanical tests and SEM analyses. Correlation between proper-ties was discussed. The comparison of mechanical and thermo-mechanical properties of the compositesshowed that electron-beam radiation treatment produced a significant improvement in mechanical prop-erties, when compared with the non-irradiated composite sample and neat HDPE. Scanning electronmicroscopy (SEM) studies of the composite failure surfaces indicated that there was an improved adhe-sion between fiber and matrix. Examination of the failure surfaces indicated dependence of the interfacialadhesion upon the radiation dose and GMA content. Better interfacial adhesion between fiber and HDPEmatrix was observed for composites with 5.0% GMA addition and treated with electron-beam radiationdose of 200 kGy. It can be concluded that GMA addition followed by electron-beam irradiation treatment,at the doses studied in this work, effectively improved the HDPE properties and led to the obtaining ofcomposite materials with superior properties suitable for several industrial applications.
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tThis work evaluates the morphology, mechanical and thermo-mechanical properties of high densitypolyethylene (HDPE) composites. HDPE reinforced with rice husk ashes (80:20 wt%), HDPE reinforcedwith clay (97:3 wt%) and HDPE reinforced with... more
tThis work evaluates the morphology, mechanical and thermo-mechanical properties of high densitypolyethylene (HDPE) composites. HDPE reinforced with rice husk ashes (80:20 wt%), HDPE reinforcedwith clay (97:3 wt%) and HDPE reinforced with both rice husk ashes and clay(77:20:3 wt%) were obtained.The Brazilian bentonite chocolate clay was used in this study. This Brazilian smectitic clay is commonlyused to produce nanocomposites. The composites were produced by melting extrusion process and thenirradiation was carried out in a 1.5 MeV electron-beam accelerator (room temperature, presence of air).Comparisons using the irradiated and non-irradiated neat polymer, and the irradiated and non-irradiatedcomposites were made. The materials obtained were submitted to tensile, flexural and impact tests.Additionally HDT, SEM and XRD analyses were carried out along with the sol–gel analysis which aimedto assess the cross-linking degree of the irradiated materials. Results showed great improvement in mostHDPE properties and a high cross-linking degree of 85% as a result of electron-beam irradiation of thematerial.