Sustainable blends of LDPE/NR and sugarcane bagasse ashes with PE-g-MA thermomechanical relationships

The polymer blends obtained with residues that before were called wastes has been growing as a viablesolution, allowing improvements in the mechanical properties and as sustainable alternative. This workreports the effects of blends of low-density polyethylene (LDPE) and natural rubber (NR), with sugarcane bagasse ash (SCBA) as filler, with and without polyethylene-graft-maleic anhydride (PE-g-MA)how coupling agent. The dynamic mechanical behavior and a stress-strain analysis were studied. Thematerials were further evaluated by differential scanning calorimetry and morphological observations.The results showed that incorporation of the PE-g-MA reduced the strain and improved the stress and theYoung module of the mixtures. Moreover, the presence of SCBA increased the hardness whilemaintaining the tensile strength and the elongation behavior of the polymer. The results demonstrate thepotential use of SCBA in the elastomer and thermoplastic mixture, free of vulcanization agents.Keywords: Sustainable blends, sugarcane bagasse ashes, natural rubber, low density polyethylene,polyethylene-graft-maleic anhydride

Compósitos preparados a partir de resíduo industrial de couro com elastômeros termoplásticos obtidos através de blendas de polietileno de baixa densidade e borracha natural

This work aimed at the development of polymr composites by mixing leather waste (RC), to use as filler, with thermoplastic elastomers obtained by the compatibility of low density polyethylene (LDPE) with natural rubber (NR) obtained latex form the rubber tree (NR) obtained latex from the rubber three (Hevea brasileiensis clone), together with curing agents, vulcanizing order to BN, for which thereby obtain the best properties of the material. The samples were produced on a HAAKE torque rheometer using roller type rotors. After the processes of rheometer, samples were pressed to occur term vulcanization of the elastomeric phase and molding of speciments. The TPEs and composites were characterized by means of mechanical, morphological, structural and thermal analysis. Based on these results, we intend to drive new material for technological applications to be used in manufacturing automobile parts, gears, among others. With this new material also pretends to direct an application to the reside of bovide leather, which is an abundant and undersirable material generated in the manufacturing of leather, which can cause serious environmental damage due to the chromium present in its structureO presente trabalho teve por objetivo o desenvolvimento de compósitos poliméricos através da mistura de resíduo de couro (RC), a ser utilizado como carga, com elastômeros termoplásticos obtidos por meio da compatibilização de polietileno de baixa densidade (PEBD) com borracha natural (BN) obtida a partir do látex de seringueira (clone de Hevera Brasiliensis), juntamente com agentes de cura, visando à vulcanização da BN, para que desta forma se obtivesse melhores propriedades do material. As amostras foram produzidas em um Reômetro de Torque (HAAKE, utilizando rotores tipo roller. Após o processo de reometria, as amostras foram termoprensadas para que ocorresse a vulcanização da fase elastomérica e moldagem dos corpos de prova. Os TPEs e os compósitos foram caracterizados por meio de análises mecânicas, morfológicas, estruturais e térmicas. Diante dos resultados obtidos, pretende-se direcionar o novo material para aplicações tecnológicas a fim de ser utilizado na fabricação peças de automóveis, engrenagens, entre outros. Com este novo material visa-se também direcionar uma aplicação ao resíduo de couro bovino, que é um material abundante e indesejável gerado na industrialização do couro, que pode causar sérios danos ambientais devido ao crono presente em sua estruturaFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Sugarcane Bagasse Ash as a Reinforcing Filler in Thermoplastic Elastomers: Structural and Mechanical Characterizations

The incorporation of residues as reinforcing fillers in polymer composites has emerged as a viable solution, enabling improvements in the mechanical properties of these materials, and has also resulted in a reduction in the cost of the final product. In this work, sugarcane bagasse ash (SBA) was used as a reinforcing filler in comparison with commercial silica (CS) in thermoplastic elastomers prepared from the compatibility of low-density polyethylene (LDPE) with natural rubber (NR). The composites were obtained by a physical mixture of LDPE and NR with different proportions of CS and SBA using a Haake rotational rheometer. The samples were analyzed by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and tensile testing. The results show that SBA has similar properties to CS, thus making its use feasible as a reinforcing filler in thermoplastic elastomers. (C) 2014 Wiley Periodicals, Inc.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Sugarcane bagasse ash: new filler to natural rubber composite

Waste recycling has been the subject of numerous scientific researches regarding the environmental care. This paper reports the redirecting of sugarcane bagasse ash (SBA) as new filler to natural rubber (NR/SBA). The NR/SBA composites were prepared using an opened cylinder mixer to incorporate the vulcanization agents and different proportions of residue (SBA). The ash contains about 70-90% of inorganic compounds, with silica (SiO2) being the main compound. The SBA incorporation improved the mechanical properties of the vulcanized rubber. Based on these results, a new use is proposed for the agro-industry organic waste to be implemented in the rubber vulcanization process, aimed at improving the rubber physical properties as well as decreasing the prices of natural rubber composites.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Natural rubber/leather waste composite foam: A new eco-friendly material and recycling approach

This article describes a new approach of recycling the leather waste (shavings) using it as filler in natural rubber foams composites. The foams were prepared using different amounts of leather waste (0-60 parts per hundred of rubber) and submitted to morphological (SEM microscopy) and mechanical analyses (cyclic stress-strain compression). The increase of leather shavings on the composite causes an increase of viscosity in the mixture, which reflects in the foaming process. This results in smaller and fairly uniform cells. Furthermore, expanded rubber has the biggest cell size, with more than 70% of cell with 1000 mu m, while the composite with the higher concentration of leather has around 80% of total number of cells with 100-400 mu m. The mechanical parameters were found to depend on the leather dust concentration. Moreover, the stiffness rises with the increase of leather shavings; consequently, the compression force for expanded rubber was 0.126 MPa as well as the composite with higher concentration of leather was 7.55 MPa. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41636

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status