DIONE PEREIRA DE CASTRO

DIONE PEREIRA DE CASTRO

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Reuse of textile waste with nano reinforcement for the development of materials incorporated with nanocomposites
2023 - SARTORI, MARIANA do N.; CASTRO, DIONE P. de; SILVA, LEONARDO G. de A. e
The use of plastics in Brazil and the world has shown a growing demand due to their qualities, ease of obtaining, and low cost, and, consequently, produces an increase of these plastics in solid urban waste. The destination of these materials, especially in Brazil, is summarized in sending to landfills, incineration and, mechanical and chemical recycling. This study evaluates the possibility of using polyamide textile waste with elastane discarded by the textile industry, as reinforcement for the development of a polymer-clay composite, on a nanometric scale, and develop a recycling route for these materials. In that, the nanocomposite technology adds value to this material. This work used polyamides from textile waste of the industry. These materials were first processed in a compacting machine. Afterward the composites with 1, 2, and 3% in mass of Verde Clara clay/polyamide were prepared in a double screw extruder. The composites were characterized by techniques of X-ray diffraction (XRD), tensile, flexural, impact tests and thermogravimetric analysis (TGA). Results obtained were compared with the properties of the standard samples. As a conclusion of this study, it can be stated that the polyamide textile scraps with elastane can be reused forming nanocomposites with Verde Clara clay. Verde Clara clay in the proportion of 1% already confers gains in the properties of these nanocomposites.
Thermal degradation and spectroscopy analysis of TPS/PBAT blends irradiated by Cobalt-60 source
2022 - CASTRO, D.P.; ANDRADE e SILVA, L.G.
This study aimed to prepare blends of natural polymers of TPS with PBAT by reactive extrusion that were subsequently subjected to the irradiation process and evaluated for their thermal and chemical properties. The blends were incorporated with plasticizers (glycerol, castor oil and surfactant) and submitted to the irradiation process using a Cobalt-60 source at a 25 kGy dose and then characterized by FTIR and DSC. The results obtained in the FTIR analysis, the blends did not undergo chemical changes during the irradiation process and thus, maintained their properties. In the DSC analysis, it was observed that the blends F2 (castor oil) and F3 (castor oil and TWEEN® 80) showed higher values of heat flow for degradation than the samples F0 (glycerol) and F1 (glycerol and TWEEN® 80), probably due to the chemical interaction of castor oil and its constituents. There was no thermal variation in the irradiation process between blends F0 and F1 or F2 and F3. It was concluded that it is feasible to replace castor oil with glycerol in TPS/PBAT blends, and that irradiation using a Cobalt-60 source did not change the properties analyzed and contributed to microbiological protection.
The incorporation of the Light Green clay in the textile polyamide residues
2021 - SARTORI, M.N.; CASTRO, D.P.; VALENZUELA-DIAZ, F.R.; SILVA, L.G.A.
The aim of this work is to evaluate the possibility to use textile residues of polyamide with elastane that are discarded by the industry as a matrix of a new polymer-clay composite material, evaluated on a manometric scale, and to propose a way of recycling for these materials. At the same time, with nanocomposite technology, value is added to this material. In this work, polyamide of textile residues from industrywas used. These materials were first processed in a compacter machine. Composites at 1, 2, and 3% by weight of Light Green clay/polyamide were prepared by double screw extrusion. The properties of the composite were characterized by X-ray diffraction (XRD), tensile, flexural, impact tests, and thermogravimetric analysis (TGA). Results obtained were compared with the neat textile polyamide properties. It was concluded that it is feasible to recycle the textile residues of polyamide, and that the addition of clay, at the doses studied in this work, could lead to the obtaining of composite materials with better mechanical than untreated ones.
Characterization of TPS/PBAT blends irradiated by ionizing radiation
2021 - CASTRO, DIONE P. de; SILVA, LEONARDO G. de A. e
The use of biodegradable polymers is an important alternative today for both the environment and industry. However, when compared to conventional polymers, biodegradables are more expensive. The development of polymeric blends using matrices of biodegradable and synthetic polymers with natural additives are less damaging to the environment and more cost efficient. This study aimed to prepare natural blends of thermoplastic starch (TPS) with poly(butylene adipate-co-terephthalate) (PBAT) by reactive extrusion. The blends were submitted to the irradiation process using a Cobalt-60 source at a 25 kGy dose and then characterized by Fourier-transform infrared spectroscopy (FTIR) and differential heat flow scanning calorimetry (DSC). According to the results obtained in the FTIR tests, the blends did not undergo chemical changes during the irradiation process and, thus, maintained their properties. In the DSC tests, it was observed that the blends F2 (composed of castor oil) and F3 (composed of castor oil and TWEEN® 80) showed higher values of heat flow for degradation than the samples F0 (composed of glycerol) and F1 (composed of glycerol and TWEEN® 80), probably due to the chemical interaction of castor oil and its constituents. There was no thermal variation in the irradiation process between blends F0 and F1 or F2 and F3 . It was concluded that it is feasible to replace castor oil with glycerol in TPS/PBAT blends.
Characterization using X-ray diffraction and study of the crystallinity of the thermoplastic starch/poly(butylene adipate-co-terephthalate) blends irradiated by gamma rays
2020 - CASTRO, DIONE P. de; GARCIA, RAFAEL H.L.; SILVA, LEONARDO G. de A. e
The aim of this study was to analyze the changes in the structure and crystallinity of non-irradiated and irradiated thermoplastic starch blends (TPS)/poly (butylene adipate-co-terephthalate) - PBAT and also to evaluate the behavior of castor oil replacing glycerol. In this work, the characterization was performed by using X-ray diffraction (XRD), in which the crystallinity index (IC) of non-irradiated and irradiated blends of TPS/PBAT was calculated, through the software Bruker DIFFRAC.EVA® v4.22. For the plastification of the TPS, glycerol, castor oil and TWEEN® 80 were used to verify their compatibility and establish a comparison among the blends. The samples were prepared by extrusion and irradiated at 25 kGy with gamma rays with a 60Co source. However, the crystallinity indexes of the blends were altered according to the plasticizer used and the use of TWEEN® 80. Thus, it was concluded that replacing glycerol with castor oil is feasible in TPS/PBAT blends.
Effects of gamma radiation on the properties of the thermoplastic starch/poly (butylene adipate-co-terephthalate) blends
2019 - CASTRO, DIONE P. de; SARTORI, MARIANA do N.; SILVA, LEONARDO G. de A. e
The development of blends made from matrices of synthetic biodegradable polymers, and natural additives, are considered less environmentally aggressive materials. This work aimed to study the effects of gamma radiation on the properties of the thermoplastic starch (TPS)/poly(butylene adipateco- terephthalate) (PBAT). In this work, blends of TPS/PBAT were prepared with glycerol, castor oil and TWEEN® 80, which were prepared by extrusion and then subjected to the radiation process and characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results demonstrated increased thermal degradation for the F2 (composed by OM) and F3 (composed by OM and TWEEN® 80) regarding F0 (composed by glycerol) e F1 (composed by glycerol and TWEEN® 80) blends. A good blend component chemical interaction and partial miscibility for the blends F0 and F1 was observed and compared to the others. However, F2 and F3 blends did not present co-continuous phases; being that the XRD curve patterns were not altered by the gamma radiation. The tests performed demonstrated that the irradiated and non-irradiated samples did not have their properties significantly altered. Thus, it was concluded that it is feasible to replace castor oi l with glycerol in TPS/PBAT blends.
XRD characterization thermoplastic STARCH/poly (butylene adipate-co-terephthalate) (TPS/PBAT) blends irradiated by gamma rays
2019 - CASTRO, DIONE P. de; GARCIA, RAFAEL H.L.; SILVA, LEONARDO G. de A. e
The aim of this research was to check the changes in the structure and crystallinity of non-irradiated and irradiated thermoplastic starch blends (TPS)/poly (butylene adipate-co-terephthalate) - PBAT and also to evaluate the behavior of castor oil in place of glycerol. In this work, the characterization was performed by X-ray diffraction (XRD), in which the crystallinity index (IC) of non-irradiated and irradiated blends of TPS/PBAT was calculated. For plastification of the TPS, glycerol, castor oil and TWEEN® 80 were used to verify the compatibility and compare the blends with each other. The samples were prepared by extrusion and irradiated at 25 kGy with gamma rays from a 60Co source. However, the crystallinity indexes of the blends were altered according to the plasticizer used and the use of TWEEN® 80. Thus, it been concluded that glycerol substitution by castor oil is feasible in TPS/PBAT blends.
Efeitos da radiação gama nas propriedades de blendas de amido termoplástico e suas misturas com poli(butileno adipato-co-tereftalato)
2019 - CASTRO, DIONE P. de
Diversas alternativas têm sido buscadas para minimizar o impacto ambiental causado pelos polímeros convencionais. Uma importante alternativa é o uso de polímeros biodegradáveis; no entanto, em razão do seu custo elevado quando comparados com polímeros convencionais, surgiu à necessidade de desenvolver misturas poliméricas biodegradáveis utilizando aditivos naturais degradáveis, menos agressivos ao meio ambiente; os quais podem ser degradados pela ação de micro-organismos ou enzimas. Este trabalho teve como objetivo preparar blendas de amido termoplástico (thermoplastic starch, TPS) obtidos com glicerol, óleo de mamona (OM) e TWEEN® 80 com poli(butileno adipato-co-tereftalato) (PBAT), por extrusão. Posteriormente as blendas foram submetidas ao processo de irradiação com dose de 25 kGy e caracterizadas por análises termogravimétrica (TGA); calorimetria exploratória diferencial por fluxo de calor (DSC); espectroscopia vibracional de absorção no infravermelho por transformada de Fourier (FTIR); microscopia eletrônica de varredura (MEV); difração de raios X (DRX) e índice de cristalinidade (IC). Os resultados mostraram maior degradabilidade térmica para as blendas F2 (compostas por OM) e F3 (compostas por OM e TWEEN®80) em relação as blendas F0 (compostas por glicerol) e F1 (compostas por glicerol e TWEEN® 80). Observou-se uma boa interação química entre os componentes das misturas e a sua miscibilidade parcial para as misturas F0 e F1, comparadas com as demais. No entanto, as misturas F2 e F3 não tiveram fases co-contínuas; sendo que as curvas padrões de DRX das amostras não foram alteradas pela radiação gama. Os IC tiveram alterações antes e após a irradiação de acordo com o plastificante utilizado. Assim, as amostras irradiadas e não irradiadas não tiveram suas propriedades alteradas nos testes realizados. Pôde-se concluir que é viável a substituição do óleo de mamona por glicerol em blendas de TPS/PBAT.
Reaproveitamento de aparas têxteis de poliamida 6 e poliamida 66 com elastano
2018 - SARTORI, M.N.; SILVA, L.G.A.; CASTRO, D.P.
O Brasil é um dos principais produtores do setor têxtil no mundo, gerando milhões de empregos diretos e indiretos. Contudo, tal atividade cria diversos problemas ao meio ambiente como, por exemplo, a geração de resíduos sólidos proveniente dos processos industriais, confeccionistas e também do pós-consumo. Muitas vezes estes resíduos são descartados de modo displicente em aterros sanitários contribuindo para o depósito de resíduos no ambiente. Neste trabalho foram utilizadas aparas têxteis de poliamida 6 e poliamida 66 com elastano que são descartadas pela indústria. Esses materiais foram processados inicialmente em uma máquina compactadora para redução de volume. Posteriormente, pelo processo de extrusão foram obtidos grânulos e por injeção foram preparados os corpos de prova os quais foram submetidos aos ensaios mecânicos de tração, flexão e impacto. Os resultados encontrados revelaram que tanto as aparas de poliamida 6 como as aparas de poliamida 66 com elastano são processáveis e apresentaram características viáveis para utilização na indústria em diferentes segmentos.
Efeito da radiação ionizante em blendas de pbat/amido plastificados com glicerol e óleo de mamona
2018 - CASTRO, D.P.; SARTORI, M.N.; SILVA, L.G.A.
Diversas alternativas têm sido buscadas para minimizar o impacto ambiental causado pelos polímeros convencionais. Uma importante alternativa é o uso de polímeros biodegradáveis; no entanto, em razão do seu alto custo quando comparados com polímeros convencionais, surge a necessidade de desenvolver misturas poliméricas biodegradáveis utilizando aditivos naturais degradáveis, tal como o amido modificado. A utilização de polímeros biodegradáveis tem mostrado ser uma alternativa viável ao uso dos materiais derivados das poliolefinas, principalmente em embalagens, pelo fato de poderem ser compostados e biodegradados após o seu descarte. O desenvolvimento de blendas poliméricas fabricadas com matrizes de polímeros biodegradáveis sintéticos, e aditivos naturais, são considerados materiais menos agressivos ao meio ambiente; os quais podem ser degradados pela ação de microorganismos ou enzimas. Neste trabalho, foram preparadas blendas de amido termoplástico (TPS) com PBAT, glicerol, óleo de mamona e TWEEN® 80, as quais, foram preparadas por extrusão, e posteriormente submetidas ao processo de radiação e caracterizadas por análises térmicas, mecânicas e morfológicas. Os resultados mostraram uma boa interação entre os componentes das blendas e sua miscibilidade, tanto irradiadas quanto não irradiadas.