Films of starch and poly(butylene adipate co-terephthalate) added of soybean oil (SO) and Tween 80

AbstractStarch extruded in the presence of a plasticizer results in a material called thermoplastic starch (TPS). TPS mixed with poly(butylene adipate co-terephthalate) (PBAT), soybean oil (SO), and surfactant may result in films with improved mechanical properties due to greater hydrophobicity and compatibility among the polymers. This study characterized films produced from blends containing 65% TPS and 35% PBAT with SO added as compatibilizer. The Tween 80 was added to prevention of phase separation. The elongation and resistance were greater in the films with SO. The infrared spectra confirmed an increase in ester groups bonded to the PBAT and the presence of groups bonded to the starch ring, indicating TPS–SO and PBAT–SO interactions. The micrographs suggest that the films with SO were more homogenous. Thus, SO is considered to be a good compatibilizer for blends of TPS and PBAT

Characterization of thermoplastic starch/poly(lactic acid) blends obtained by extrusion and thermopressing

Blends of poly(lactic acid) (PLA)/thermoplastic starch (TPS) were prepared by extrusion and thermopressing, with proportions of 0.1, 0.2 and 0.3 g of PLA per g TPS. Thermoplastic starch was obtained from the extrusion of 0.30 g or 0.25 g of glycerol per g of starch. The mechanical properties and water vapor permeability were tested and water sorption isotherms were obtained. The morphological characteristics of the samples were observed through scanning electron microscopy (SEM) and the thermal properties of the pure polymers and the blends by differential scanning calorimetry (DSC). The SEM and DSC results indicated the immiscibility of the TPS/PLA blends and the presence of two phases. For blends with 20% and 30% of PLA increases in the tensile strength and modulus were observed. The lowest water vapor permeability was observed for the blend with 30% of PLA, which is related to the lowest diffusion coefficient value observed for this sample

Effect of cooling and coating on thermoplastic starch/poly(lactic acid) blend sheets

AbstractThe influence of the processing conditions (cooling rate) and coating on the physicochemical properties of thermoplastic starch/poly(lactic acid) blend sheets was studied. Two cooling rates were used: fast and slow, and in the latter case the sheets were both non-coated and coated with cross-linked chitosan. The physicochemical properties investigated were crystallinity, morphology, water affinity (moisture sorption isotherm, water vapor permeability, water solubility and contact angle) and mechanical properties. In general, the sheets cooled at the slow rate were more crystalline, less permeable and less soluble in water than those cooled at the fast rate. They also produced a more homogeneous morphology. The coated sheets were less soluble in water and mechanically stronger than uncoated sheets cooled at the slow rate. The concentration of plasticizer in the TPS affected only the sorption isotherm and contact angle since a higher plasticizer content caused a greater affinity for water

Mecanismos Intracelulares da Hipertrofia Muscular: Por que o Músculo Aumenta de Tamanho quando Realizamos Exercícios com Pesos? Uma Revisão de Literatura: Intracellular Mechanisms of Muscle Hypertrophy: Why Does Muscle Increase in Size When Exercing with Weights? A Literature Review

A busca pelo aumento da massa magra é um desejo de grande parte da população. Muitas pessoas procuram a academia para levantar pesos e aumentar o tamanho dos músculos. No entanto, grande parte desse público não sabe quais são os mecanismos que promovem essas modificações e terminam abandonando o programa de hipertrofia muscular antes de alcançar os resultados desejados. Foi demonstrado que muitos fatores mediam o processo hipertrófico, e a maioria é induzido pelo exercício, tais como tensão mecânica, dano muscular e estresse metabólico. Portanto, o objetivo deste artigo é descrever as principais vias de sinalização envolvidas na hipertrofia, ou aumento da área de sessão transversa do músculo

Elaboração e caracterização de filmes extrusados a partir de blendas de poli (adipato-co-tereftalato de butileno) e farinha de trigo com diferentes Falling number / Elaboration and characterization of extruded films from blends of poly (butylene adipate-co-terephthalate) and wheat flour with different Falling number

O objetivo deste trabalho foi produzir filmes por extrusão sopro em balão a partir de farinha de trigo com diferentes valores de falling number (FN), glicerol e PBAT. Foram realizadas análises de FN, alveografia e cor da farinha de trigo e nos filmes determinou-se as propriedades mecânicas, permeabilidade ao vapor de água (PVA) e cor. Foram selecionados dois tipos de farinha de trigo com os seguintes valores de FN: 184 s (baixo, FNB) e 364 s (alto, FNA). As amostras de farinha de trigo apresentaram diferenças significativas para todos os parâmetros de cor (L*, a* e b*) e essa diferença também se manteve para os filmes. Os filmes apresentaram luminosidade (L*) menor (88,48 ± 0,54 para FNB e 89,31 ± 0,40 para FNA) em relação às farinhas (91,18 ± 0,04 para FNB e 92,64 ± 0,03 para FNA), sugerindo a ocorrência de reação de Maillard durante o processamento do filme por extrusão. Com relação às propriedades mecânicas, apenas o alongamento na ruptura apresentou diferença significativa (559 ± 65,69 % para filmes FNB e 420 ± 62,44 % para filmes FNA) sendo estes resultados semelhantes aos filmes de polietileno de baixa densidade. As farinhas com diferentes FN não interferiram na PVA dos filmes. O uso de farinhas com diferentes FN não interferem nas propriedades dos filmes produzidos por extrusão sopro em balão, sugerindo que a farinha de trigo de baixo FN, normalmente de menor interesse industrial, é uma matéria-prima interessante para produção de embalagens biodegradáveis

Scaling up Electronic Spin Qubits into a Three-Dimensional Metal-Organic Framework

Practical implementation of highly coherent molecular spin qubits for challenging technological applications, such as quantum information processing or quantum sensing, requires precise organization of electronic qubit molecular components into extended frameworks. Realization of spatial control over qubit–qubit distances can be achieved by coordination chemistry approaches through an appropriate choice of the molecular building blocks. However, translating single qubit molecular building units into extended arrays does not guarantee a priori retention of long quantum coherence and spin–lattice relaxation times due to the introduced modifications over qubit–qubit reciprocal distances and molecular crystal lattice phonon structure. In this work, we report the preparation of a three-dimensional (3D) metal–organic framework (MOF) based on vanadyl qubits, [VO­(TCPP-Zn2-bpy)] (TCPP = tetracarboxylphenylporphyrinate; bpy = 4,4′-bipyridyl) (1), and the investigation of how such structural modifications influence qubits’ performances. This has been done through a multitechnique approach where the structure and properties of a representative molecular building block of formula [VO­(TPP)] (TPP = tetraphenylporphyrinate) (2) have been compared with those of the 3D MOF 1. Pulsed electron paramagnetic resonance measurements on magnetically diluted samples in titanyl isostructural analogues revealed that coherence times are retained almost unchanged for 1 with respect to 2 up to room temperature, while the temperature dependence of the spin–lattice relaxation time revealed insights into the role of low-energy vibrations, detected through terahertz spectroscopy, on the spin dynamics

Araucaria angustifolia (Bertol.) Kuntze extract as a source of phenolic compounds in TPS/PBAT active films

There is growing interest in the development of biodegradable packaging materials containing natural antioxidant extracts. In this sense, the use of extracts obtained from agro-industrial byproducts has proved to be a sustainable alternative. In this study, Pinhão extract, a byproduct of Pinhão (Araucaria angustifolia (Bertol.) Kuntze) seed consumption, was characterized by HPLC-DAD-ESI/MSn, demonstrating the presence of eight phenolic compounds, (+)-catechin and (−)-epicatechin being the most abundant molecules. TPS/PBAT films containing Pinhão extract were produced by blown extrusion and their properties (tensile properties, thermal characteristics and microstructure) were evaluated in order to determine the effect of the presence of extracts. Results suggested that the interaction between the phenolic compounds of the extract and the polymeric matrix caused the reduction in the crystallinity degree, and an increase in the starch glass transition temperature. The presence of Araucaria angustifolia (Bertol.) Kuntze extract significantly (p < 0.05) affected the color and opacity of the film. Regarding water vapor permeation, no significant difference (p > 0.05) was detected. However, the water solubility and the contact angle with water (polar solvent) and diiodomethane (non-polar solvent) significantly changed due to the extract addition. Moreover, the Pinhão extract conferred significant antioxidant capacity to the TPS/PBAT films as determined by DPPH, suggesting that this material can be applied as an active packaging material.The authors thank CNPq (Chamada Universal – MCTI/CNPq no. 14/2014, Processo 447768/2014-0), CAPES (Master’s scholarship) and Fundação Araucária (Programa Universal/ Pesquisa Básica e Aplicada 24/2012, protocolo 7334133700514041013) for the financial support and they also thank Associate Laboratory LSRE-LCM – UID/EQU/50020/2019 – funded by national funds through FCT/MCTES (PIDDAC) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2019) and to the national funding by FCT, P.I., through the institutional scientific employment program-contract for L. Barros contracts. The authors are also grateful to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

Assessment of the conditions of the thermoplastic extrusion process in the bioactive and mechanical properties of flexible films based on starch and Brazilian pepper

[EN] The objective of this work was to produce, through the thermoplastic extrusion process followed by blowing, manioc starch-based flexible films added with Brazilian pepper oil as an antioxidant and plasticizer agent, and verify if the bioactive compounds contained in the fresh pepper oil are present after the drying step of the thermoplastic extrusion. After analysis by gas chromatography-mass spectrometry volatiles compounds were identified in the films. Pepper oil also influenced the mechanichal properties of the films.These results suggest that the temperatures used in the process, kept some of the existing compounds in the Brazilian pepper essential oil adhered to the packages.Authors are grateful to TECNIOspring program.Fakhouri, F.; Freitas Delima, F.; Cardoso, C.; Martelli, S.; Antunes, M.; Mei, L.; Yamashita, F.... (2018). Assessment of the conditions of the thermoplastic extrusion process in the bioactive and mechanical properties of flexible films based on starch and Brazilian pepper. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1979-1985. https://doi.org/10.4995/IDS2018.2018.7780OCS1979198

Avaliação físico-química e sensorial de manteiga adicionada de óleo essencial de orégano e em embalagem biodegradável

Atualmente há uma crescente preocupação em relação ao uso de conservantes artificiais, estudos sobre a aplicação de antioxidantes naturais tanto nas formulações quanto em embalagens ativas são de grande importância para melhoria da qualidade nutricional de produtos alimentícios. Assim, o presente trabalho teve como objetivo desenvolver e avaliar amostras de manteiga aplicando de óleo de orégano. Foram desenvolvidas três formulações de manteiga: padrão, adicionada de 0,005% de óleo essencial de orégano e padrão embalada em filme biodegradável contendo 1% de óleo essencial de orégano. As amostras foram armazenadas a 5ºC durante 60 dias. As mesmas foram caracterizadas quanto à umidade, cinzas, acidez, gordura, extrato seco desengordurado, oxidação lipídica, textura e cor instrumental. Os atributos sensoriais avaliados por escala hedônica de nove pontos foram cor, aroma, textura, sabor e a intenção de compra por escala de três pontos. Após 60 dias não houve diferença na composição química das amostras para todos os parâmetros. Com relação à análise sensorial, a formulação com maiores notas foi a padrão e a adicionada de 0,005% de óleo essencial de orégano. Em geral, conclui-se que a adição de óleo essencial de orégano é viável, uma vez que o produto foi bem aceito pelos consumidores