In this work, two formulations of pectin/cellulose nanocrystals/glycerol nanocomposites were employed as packaging to extend storage life of strawberries. The effects of incorporating cellulose nanocrystals extracted from bleached Kraft wood pulp on the mechanical, thermal, and barrier properties of pectin-based nanocomposites were evaluated. Nanocomposite films with different filler levels of cellulose nanocrystals (1, 2, 4 and 8% w/w) were prepared by casting. Compared with the neat film of pectin, improvements in the mechanical properties of the nanocomposites were observed, but these films became fragile. To improve the film flexibility, glycerol was added as a plasticizer and then new variations in the mechanical, thermal, and barrier properties of these nanocomposites were evaluated. The effects of nanocomposite films on storability of strawberries were compared with Poly vinyl chloride packaging films. The Poly vinyl chloride film and the nanocomposites showed similar behavior regarding weight loss by the strawberries, especially in the initial days of storage. The results show that pectin/cellulose nanocrystals/glycerol nanocomposites could be considered as a viable packaging alternative for replaced the Poly vinyl cloride film.

diferentes tipos de serragem gerados na indústria moveleira. Os compósitos foram produzidos por extrusão, utilizando-se uma extrusora monorrosca de 35 mm e temperaturas de 160°C, 170 °C e 180 °C nas zonas 1, 2 e 3, respectivamente. Foram utilizados resíduos de madeira de pinus (Pinus taeda), de aglomerado, de chapa de fibra de média densidade (MDF) e madeira de eucalipto (Eucalyptus grandis), que foram incorporados ao HDPE "virgem", juntamente com um agente de acoplamento à base de anidrido maléico. Para caracterização física dos compósitos, foram realizadas análises por calorimetria diferencial de varredura (DSC) e por microscopia eletrônica de varredura (SEM). Foram também analisadas as propriedades mecânicas de resistência à tração, flexão estática e resistência ao impacto, conforme as normas ASTM D638, D790 e D256. Verificou-se que todos os tipos de serragem agiram como agentes nucleantes, pois os compósitos apresentaram índices de cristalinidade maiores que o v-HDPE puro, e houve influência do tipo de serragem usada na dispersão das fibras na matriz polimérica. Os ensaios mecânicos indicaram diferenças nas propriedades dos compósitos confeccionados com diferentes tipos de serragem. De maneira geral, a inclusão de serragem de aglomerado e de eucalipto proporcionaram compósitos com maior resistência à flexão e ao impacto que aqueles fabricados com MDF e pinus.Palavras-chave: Compósitos, HDPE e serragem. CHARACTERIZATION OF COMPOSITES MADE FROM HIGH DENSITY POLYTHYLENE (HDPE) AND FURNITURE INDUSTRY SAWDUST

In this work, nine different types of edible coating based on pectin, cellulose nanocrystals, glycerol, and essential oil of lemongrass were prepared and used to coat strawberries with a film formed directly on the surface of the coated fruit. The effects of the different edible coatings on refrigerated fruits in terms of weight loss, titratable acidity, total soluble solids, pH, and anthocyanin content was evaluated after 2 days, 4 days, 6 days, and 8 days of storage. Application of the edible coatings reduced the weight loss of the coated strawberries and the anthocyanin content. The total soluble solids content of or uncoated fruit increase more markedly than that of coated fruit. In contrast, pH was maintained for both coated and uncoated strawberries. The edible coatings were effective in minimizing of the weight loss, without worsening the physical chemistry attributes. The treatments T5 and T9 presented the best results.

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The membrane separation capacity allows the retention of the remaining organic matter that could not be removed by the biological process, increasing the treatment efficiency. The aim of this study was to evaluate the microfiltration (MF) process in a tertiary treatment system for landfill leachate from the Rincão das Flores, Caxias do Sul/RS/Brazil. The microfiltration system of commercial hollow fiber membrane poly(etherimide) was tested in oder to promote leachate treatment. The tests carried out were leachate permeation, concentration factor, determination of fouling and obtention of the values of the resitance to the flux. The resistance due to fouling and flux decline were evaluated to determine the best operating conditions. The potential for fouling was 53% and was evaluated by comparing the pure water permeability before and after the leachate filtration. It was observed that the resistance due to fouling express 32% of the total resistance. The results showed that the MF process allows the elimination of up to 43% of the organic matter measured as chemical oxygen demand (COD) and 63% of that measured as biological oxygen demand (BOD 5 ).

In this work, ethylene‐co‐vinyl acetate (EVA), poly(ethylene‐co‐octene) (POE), and poly(vinyl chloride) (PVC) blends were processed in a molten state process using a corotating twin‐screw extruder to assess both the balance of mechanical properties and physical interactions in the melt state. Tensile measurements, scanning electron microscopy, and oscillatory rheometry were performed. By means of flow curves, the parameters of the power law as well as the distribution of relaxation times were assessed with the aid of a nonlinear regularization method. The mechanical properties for the EVA‐POE blend approximated the values for POE, while inclusion of PVC shifted the modulus values to those of neat EVA. The rise in modulus was corroborated by the PVC phase dispersion as solid particles that act as a reinforcement for the ternary blend. The rheological properties in the molten state show that the POE does not present molecular entanglement effects and so tends both to diminish the EVA mechanical properties and increase the fluidity of the blend. However, the addition of PVC both restored the EVA typical pseudoplastic feature and promoted the increase in the viscosity and the mechanical properties of the ternary blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

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This study aims to evaluate the influence of types I and II coagents on different polybutadiene isomers vulcanized with organic peroxides. In this study, dicumyl peroxide (DCP) is used in association with coagents ethylene glycol dimethacrylate (EGDMA) and triallyl isocianurate (TAIC) in the crosslinking of high cis‐1,4‐polybutadiene and high vinyl‐1,2‐polybutadiene isomers. The results reveal that using a type I coagent, EGDMA increases the crosslink density as the amount of coagent is increased. The curing index of the samples is positively influenced by coagent type I, mainly when vinyl‐1,2‐polybutadiene is used.