Ademir Zattera - Academia.edu (original) (raw)

Papers by Ademir Zattera

A low-cost and easy-to-handle manufacturing procedure for urban trash containers, made of recycle... more A low-cost and easy-to-handle manufacturing procedure for urban trash containers, made of recycled plastic lumber, was developed focusing on the following aspects: materials selection, materials compounding, plastic sheet manufacturing and me-chanical testing, urban trash container design and assembly, and a pilot test. The material, a composite of polyethylene (PE) urban waste, ethylene-vinyl acetate copolymer (EVA) industrial waste and calcium carbonate, was prepared in a Drais batch mixer. The mixture was hot compression molded as rectangular-shaped sheets of 900 mm length, 600 mm width and 12 mm or 7 mm thickness. These sheets were characterized with regard to mechanical properties, microstructure and UV resistance. An urban trash container prototype was prepared from the plastic sheets and a hundred trash containers were submitted to a pilot test. All the steps, material compounding, plastic sheet processing, and trash container design and manufacturing were optimized in order ...

of clays were used: Na + , 15A and 30B. The dynamic mechanical properties were analyzed using a D... more of clays were used: Na + , 15A and 30B. The dynamic mechanical properties were analyzed using a DMA Analyzer 2980. The storage modulus show higher values for the samples containing the organophilic clays, mainly in the glassy region. These results were better visualized calculating the storage modulus retention. The loss modulus show lower energy dissipation for the nanocomposite containing 15A clay and this can be indicative of a strong interface between matrix/reinforcement and/or a better dispersion promoting more interface regions, when compared to the others clays. The glass transition (Tg) show a shift to higher temperatures with incorporation of 15A and 30B nanoclays indicating more thermal energy to begin the cooperative motion. Also, by integrating the tan delta curve was obtained the peak width at half-height and the peak width of the samples. The results show lower values for the sample 15A for both analyses and, this can be indicative of a more homogeneous system in comp...

Progress in Rubber, Plastics and Recycling Technology

An alternative approach for the reuse of waste textiles fabric (WTF) of cotton and polyacrylonitr... more An alternative approach for the reuse of waste textiles fabric (WTF) of cotton and polyacrylonitrile was investigated with the purpose of to reinforce high density polyethylene (HDPE) and in addition, a new methodology for obtaining the composites was also developed. It was found that the resulting mechanical properties tested were function of the fibers content. In order to improve the performance of these composite materials, 5 phr (part hundred resin) of maleic anhydride grafted high density polyethylene (HDPEgMAH) was used as compatibiliser. It is believed that the addition of a reactive compatibilizer to the system increased both the compatibility among components of the composite material and interfacial interactions.

Revista Árvore

In this study, composites with three types of thermoplastic matrix and cellulosic material in a p... more In this study, composites with three types of thermoplastic matrix and cellulosic material in a proportion of 40% were produced. The three thermoplastic matrices were high density polyethylene (HDPE), polypropylene (PP) and low density polyethylene (LDPE), and the cellulosic materials were pure wood flour (Pinus taeda L) or a mixture of wood flour and coconut shell flour (Cocus nucifera L) in equal ratios. The objective was to evaluate the influence of addition of coconut shell on the physico-mechanical properties (density, strength and rigidity) and the distribution of the cellulosic material in the thermoplastic matrix of the manufactured composites. It was found that the composites had a satisfactory distribution of wood flour in thermoplastic matrices, but the addition of coconut shell promoted bubble formation in the resulting pieces and, thus, interfered with the material properties. The use of a coupling agent promoted interfacial adhesion (cellulose - thermoplastic matrix), ...

Cellular Polymers

ABSTRACT This paper presents a characterization of a crosslinked EVA residue (EVA-c) from expande... more ABSTRACT This paper presents a characterization of a crosslinked EVA residue (EVA-c) from expanded sheets used in the shoe industry and post-consumer urban-waste polyethylenes regarding their molecular (FTIR), mechanical (tensile and impact tests), morphological(SEM), thermal(DSC, TGA)and dynamic-mechanical(DMTA) properties. For comparison, the properties of the EVA-c and recycled polyethylenes are compared to respective virgin polymers. The recycled polyethylenes generally presented similar properties to the virgin ones. On the other hand, some EVA-c properties differed from virgin ones since it has a high degree of crosslinking and. it therefore has a higher tensile modulus and lower elongation at break, notched Izod impact strength and hardness. Additionally, crosslinking was also found to modify the thermal properties (TGA and DSC) of EVA-c.

Matéria (Rio de Janeiro)

RESUMO A adição de micropartículas em materiais cimentícios é um método que vem sendo investigado... more RESUMO A adição de micropartículas em materiais cimentícios é um método que vem sendo investigado nas últimas décadas, apresentando a possibilidade de melhorar o desempenho mecânico destes materiais. Este estudo tem como objetivo avaliar a influência causada pela adição de uma micropartícula, a microcelulose cristalina (MCC), nas propriedades mecânicas de argamassas cimentícias. Esta avaliação se deu por meio da utilização de diferentes dosagens de MCC, em relação à massa de cimento, e um fator a ser destacado é a busca pela manutenção da trabalhabilidade da argamassa cimentícia, por meio do ajuste em sua relação água/cimento. Foram realizados ensaios de determinação de índice de consistência, resistência à compressão, resistência à tração na flexão, ensaios de absorção e também a captura de imagens das argamassas por meio da Microscopia Eletrônica de Varredura (MEV). De acordo com os resultados dos ensaios, constatou-se que, entre as dosagens de MCC analisadas, as argamassas com ad...

Journal of Urban and Environmental Engineering, 2016

Solid waste management is become a challenge for the cities’ authorities in developing countries ... more Solid waste management is become a challenge for the cities’ authorities in developing countries mainly due rapid economic growth and population increasing. In cities of the developing world, the informal sector plays an important role in the management of urban solid waste. This work examines the participation of scavengers in an integrated municipal solid waste management system. The paper is based on direct field observations, interviews with scavengers and characterization of the urban solid waste generated in Caxias do Sul. The partnership between municipal government and local scavengers were also evaluated as well as the contribution of the scavengers in the urban solid waste management system. The study reveals that is necessary realize a campaign for improve the waste segregation at source, the infrastructure of the scavengers associations need to be improved and finally the scavengers need to be more deeply involved in the policies associated with the urban solid waste man...

Carbohydrate Polymers, 2016

Tobacco stems waste underwent steam explosion pulping for nanofibrillated cellulose (NFC) product... more Tobacco stems waste underwent steam explosion pulping for nanofibrillated cellulose (NFC) production. In order to obtain NFC hydrogels, the pulp obtained by steam explosion was bleached and refined in a grinder employing specific energy of up to 5067kWh/t. Eucalyptus kraft pulp was processed under the same conditions to produce NFC hydrogels, later used in order to compare with NFC hydrogels from tobacco stems waste. According to statistical analysis, the optimum tobacco stems pulping condition was obtained with a severity index of log3.0 and active alkali of 16.25%. These conditions allowed obtaining a bleached pulp with Schopper Riegler degree of 46. Electronic microscopy with field emission showed a higher presence of nanofibers in the tobacco stems pulp than in commercial eucalyptus kraft pulp, both after refining. Thermal analysis indicated that tobacco stems pulp degrade at lower temperatures than eucalyptus kraft pulp. FTIR analysis did not indicate chemical bonding differences between the two pulps.

A low-cost and easy-to-handle manufacturing procedure for urban trash containers, made of recycle... more A low-cost and easy-to-handle manufacturing procedure for urban trash containers, made of recycled plastic lumber, was developed focusing on the following aspects: materials selection, materials compounding, plastic sheet manufacturing and me-chanical testing, urban trash container design and assembly, and a pilot test. The material, a composite of polyethylene (PE) urban waste, ethylene-vinyl acetate copolymer (EVA) industrial waste and calcium carbonate, was prepared in a Drais batch mixer. The mixture was hot compression molded as rectangular-shaped sheets of 900 mm length, 600 mm width and 12 mm or 7 mm thickness. These sheets were characterized with regard to mechanical properties, microstructure and UV resistance. An urban trash container prototype was prepared from the plastic sheets and a hundred trash containers were submitted to a pilot test. All the steps, material compounding, plastic sheet processing, and trash container design and manufacturing were optimized in order ...

of clays were used: Na + , 15A and 30B. The dynamic mechanical properties were analyzed using a D... more of clays were used: Na + , 15A and 30B. The dynamic mechanical properties were analyzed using a DMA Analyzer 2980. The storage modulus show higher values for the samples containing the organophilic clays, mainly in the glassy region. These results were better visualized calculating the storage modulus retention. The loss modulus show lower energy dissipation for the nanocomposite containing 15A clay and this can be indicative of a strong interface between matrix/reinforcement and/or a better dispersion promoting more interface regions, when compared to the others clays. The glass transition (Tg) show a shift to higher temperatures with incorporation of 15A and 30B nanoclays indicating more thermal energy to begin the cooperative motion. Also, by integrating the tan delta curve was obtained the peak width at half-height and the peak width of the samples. The results show lower values for the sample 15A for both analyses and, this can be indicative of a more homogeneous system in comp...

Progress in Rubber, Plastics and Recycling Technology

An alternative approach for the reuse of waste textiles fabric (WTF) of cotton and polyacrylonitr... more An alternative approach for the reuse of waste textiles fabric (WTF) of cotton and polyacrylonitrile was investigated with the purpose of to reinforce high density polyethylene (HDPE) and in addition, a new methodology for obtaining the composites was also developed. It was found that the resulting mechanical properties tested were function of the fibers content. In order to improve the performance of these composite materials, 5 phr (part hundred resin) of maleic anhydride grafted high density polyethylene (HDPEgMAH) was used as compatibiliser. It is believed that the addition of a reactive compatibilizer to the system increased both the compatibility among components of the composite material and interfacial interactions.

Revista Árvore

In this study, composites with three types of thermoplastic matrix and cellulosic material in a p... more In this study, composites with three types of thermoplastic matrix and cellulosic material in a proportion of 40% were produced. The three thermoplastic matrices were high density polyethylene (HDPE), polypropylene (PP) and low density polyethylene (LDPE), and the cellulosic materials were pure wood flour (Pinus taeda L) or a mixture of wood flour and coconut shell flour (Cocus nucifera L) in equal ratios. The objective was to evaluate the influence of addition of coconut shell on the physico-mechanical properties (density, strength and rigidity) and the distribution of the cellulosic material in the thermoplastic matrix of the manufactured composites. It was found that the composites had a satisfactory distribution of wood flour in thermoplastic matrices, but the addition of coconut shell promoted bubble formation in the resulting pieces and, thus, interfered with the material properties. The use of a coupling agent promoted interfacial adhesion (cellulose - thermoplastic matrix), ...

Cellular Polymers

ABSTRACT This paper presents a characterization of a crosslinked EVA residue (EVA-c) from expande... more ABSTRACT This paper presents a characterization of a crosslinked EVA residue (EVA-c) from expanded sheets used in the shoe industry and post-consumer urban-waste polyethylenes regarding their molecular (FTIR), mechanical (tensile and impact tests), morphological(SEM), thermal(DSC, TGA)and dynamic-mechanical(DMTA) properties. For comparison, the properties of the EVA-c and recycled polyethylenes are compared to respective virgin polymers. The recycled polyethylenes generally presented similar properties to the virgin ones. On the other hand, some EVA-c properties differed from virgin ones since it has a high degree of crosslinking and. it therefore has a higher tensile modulus and lower elongation at break, notched Izod impact strength and hardness. Additionally, crosslinking was also found to modify the thermal properties (TGA and DSC) of EVA-c.

Matéria (Rio de Janeiro)

RESUMO A adição de micropartículas em materiais cimentícios é um método que vem sendo investigado... more RESUMO A adição de micropartículas em materiais cimentícios é um método que vem sendo investigado nas últimas décadas, apresentando a possibilidade de melhorar o desempenho mecânico destes materiais. Este estudo tem como objetivo avaliar a influência causada pela adição de uma micropartícula, a microcelulose cristalina (MCC), nas propriedades mecânicas de argamassas cimentícias. Esta avaliação se deu por meio da utilização de diferentes dosagens de MCC, em relação à massa de cimento, e um fator a ser destacado é a busca pela manutenção da trabalhabilidade da argamassa cimentícia, por meio do ajuste em sua relação água/cimento. Foram realizados ensaios de determinação de índice de consistência, resistência à compressão, resistência à tração na flexão, ensaios de absorção e também a captura de imagens das argamassas por meio da Microscopia Eletrônica de Varredura (MEV). De acordo com os resultados dos ensaios, constatou-se que, entre as dosagens de MCC analisadas, as argamassas com ad...

Journal of Urban and Environmental Engineering, 2016

Solid waste management is become a challenge for the cities’ authorities in developing countries ... more Solid waste management is become a challenge for the cities’ authorities in developing countries mainly due rapid economic growth and population increasing. In cities of the developing world, the informal sector plays an important role in the management of urban solid waste. This work examines the participation of scavengers in an integrated municipal solid waste management system. The paper is based on direct field observations, interviews with scavengers and characterization of the urban solid waste generated in Caxias do Sul. The partnership between municipal government and local scavengers were also evaluated as well as the contribution of the scavengers in the urban solid waste management system. The study reveals that is necessary realize a campaign for improve the waste segregation at source, the infrastructure of the scavengers associations need to be improved and finally the scavengers need to be more deeply involved in the policies associated with the urban solid waste man...

Carbohydrate Polymers, 2016

Tobacco stems waste underwent steam explosion pulping for nanofibrillated cellulose (NFC) product... more Tobacco stems waste underwent steam explosion pulping for nanofibrillated cellulose (NFC) production. In order to obtain NFC hydrogels, the pulp obtained by steam explosion was bleached and refined in a grinder employing specific energy of up to 5067kWh/t. Eucalyptus kraft pulp was processed under the same conditions to produce NFC hydrogels, later used in order to compare with NFC hydrogels from tobacco stems waste. According to statistical analysis, the optimum tobacco stems pulping condition was obtained with a severity index of log3.0 and active alkali of 16.25%. These conditions allowed obtaining a bleached pulp with Schopper Riegler degree of 46. Electronic microscopy with field emission showed a higher presence of nanofibers in the tobacco stems pulp than in commercial eucalyptus kraft pulp, both after refining. Thermal analysis indicated that tobacco stems pulp degrade at lower temperatures than eucalyptus kraft pulp. FTIR analysis did not indicate chemical bonding differences between the two pulps.