Sorção de petróleo por fibras vegetais

Nowadays, when accidents with oil tanker or shore tanks occur and there is oil spill, some arrangements are made in order to repress and to fix the situation. For the containment, barriers or detours are usually made of synthetic materials such as polyurethane foam. In order to clear water away, techniques like in loco burning, biodegradant agents, dispersant agents and sorbent materials application are used. The most of the sorbent materials are also synthetic and they are used because it is easy to store them and their availability in market. This dissertation introduces the study of vegetable fibers of pineapple leaf fibers (Ananas comosus (L.) Merr.), cotton fibers (Gossypium herbaceum L.), kapok fibers (Ceiba pentandra (L.) Gaertn.), curauá fibers (Ananas erectifolius L.B. Sm.) and sisal fibers (Agave sisalana Perrine) related to their capacity of sorption of oil in case of accidental spill in the ocean. This work evaluates the substitution possibility of synthetic materials by natural biodegradable materials with less cost

Desempenho mecânico de compósitos híbridos de fibras naturais e poliéster não saturado

With the objective to promote sustainable development, the fibres found in nature in abundance, which are biodegradable, of low cost in comparison to synthetic fibres are being used in the manufacture of composites. The mechanical behavior of the curauá and pineapple leaf fibre (PALF) composites in different proportions, 25% x 75% (P1), 50% x 50% (P2) e 75% x 25% (P3) were respectively studied, being initially treated with a 2% aqueous solution of sodium hydroxide. Mechanical analyses indicated that with respect to studies of traction, for the combination of P1 and P3, better results of 22.17 MPa and 16.98 MPa, were obtained respectively, which are higher than that of the combination P2. The results of the same pattern were obtained for analysis of bending resistance where P1 is 1.21% and P3 represents 0.96%. In the case of resistance to bending, best results were obtained for the combination P1 at 49.07 MPa. However, when Young's modulus values were calculated, the values were different to the pattern of the results of other tests, where the combination P2 with the value of 4.06 GPa is greater than the other combinations. This shows that the PALF had a greater influence in relation to curauá fibre. The analysis of the results generally shows that in combinations of two vegetable fibers of cellulosic origin, the fiber which shows higher percentage (75%) is the best option than to the composition of 50%/50%. In the meantime, according to the results obtained in this study, in the case where the application should withstand bending loads, the better composition would be 50%/50%

Estudo da flamabilidade e resistência à chama de compósito de poliéster insaturado e fibra da folha do abacaxizeiro (PALF)

In the present research work, composites were prepared using pine apple leaf fibres (PALF) as reinforcement with unsaturated polyester resin as matrix, incorporating with fire retardant at different compositions. The PALF was obtained from the decortication of pine apple leaves obtained from Ramada 4 from Ielmo Marinho in the State of Rio Grande do Norte. The unsaturated polyester resin and the catalyzer were bought from the local establishment. The fire retardant, aluminium tri-hydroxide - Al(OH)3 was donated by Alcoa Alumínio S.A and was used in the proportions of 20%, 40% and 60% w/w. Initially the fibres were treated with 2% NaOH for 1 hour, to remove any impurities present on the fibre surface, such as wax, fat, pectin and pectate, in order to have a better adsorption of the fibres with the matrix as well as the flame retardant. The fibre mat was prepared in a mat preparator by immersion, developed in the Textile Engineering Laboratory, at the UFRN. The composites (300x300x3 mm) were prepared by compression molding and the samples (150x25x3 mm) for analysis of the properties were cut randomly using a laser cutter. Some of the cut samples were used to measure the smoke emission and fire resistance using UL94 standard. Mechanical tension-extension and flexural properties were carried in CTGás RN and the Laboratório de Metais e Ensaios Mecânicos Engenharia de Materiais UFRN , as well as SEM studies were carried out at Núcleo de Estudos em Petróleo e Gás Natural - UFRN . From the observed results, it was noted that, there was no marked influence of the fire retardant on the mechanical properties. Also in the water absorption test, the quantity of water absorbed was less in the sample with higher concentration of fire retardant. It was also observed that the increase in the proportion of the fire retardant increased the time of burning, may be due to the compactness of the composite due to the presence of fire retardant as a filling material even though it was meant to reduce the rate of inflammability of the composite

Desenvolvimento de uma desfribadeira para obtenção da fibra da folha do abacaxi

In 1998 the first decorticator was developed in the Textile Engineering Laboratory and patented for the purpose of extracting fibres from pineapple leaves, with the financial help from CNPq and BNB. The objective of the present work was to develop an automatic decorticator different from the first one with a semiautomatic system of decortication with automatic feeding of the leaves and collection of the extracted fibres. The system is started through a command system that passes information to two engines, one for starting the beater cylinder and the other for the feeding of the leaves as well as the extraction of the decorticated fibres automatically. This in turn introduces the leaves between a knife and a beater cylinder with twenty blades (the previous one had only 8 blades). These blades are supported by equidistant flanges with a central transmission axis that would help in increasing the number of beatings of the leaves. In the present system the operator has to place the leaves on the rotating endless feeding belt and collect the extracted leaves that are being carried out through another endless belt. The pulp resulted form the extraction is collected in a tray through a collector. The feeding of the leaves as well as the extraction of the fibres is controlled automatically by varying the velocity of the cylinders. The semi-automatic decorticator basically composed of a chassis made out of iron bars (profile L) with 200cm length, 91 cm of height 68 cm of width. The decorticator weighs around 300Kg. It was observed that the increase in the number of blades from 8 to twenty in the beater cylinder reduced the turbulence inside the decorticator, which helped to improve the removal of the fibres without any problems as well as the quality of the fibres. From the studies carried out, from each leaf 2,8 to 4,5% of fibres can be extracted. This gives around 4 to 5 tons of fibres per hectare, which is more than that of cotton production per hectare. This quantity with no doubt could generate jobs to the people not only on the production of the fibres but also on their application in different areas

Desenvolvimento de bionanocompósitos: nano e microcristais de celulose com poli (álcool vinílico) e poli (ácido lático)

This work has the main objective to obtain nano and microcrystals of cellulose, extracted from the pineapple leaf fibres (PALF), as reinforcement for the manufacture of biocomposite films with polymeric matrices of Poly(vinyl alcohol) (PVA) and Poly(lactic acid) (PLA). The polymer matrices and the nano and microcrystals of cellulose were characterised by means of TGA, FTIR and DSC. The analysis was performed on the pineapple leaves to identify the macro and micronutrients. The fibers of the leaves of the pineapple were extracted in a desfibradeira mechanical. The PALF extracted were washed to remove washable impurities and subsequently treated with sodium hydroxide (NaOH) and sodium hypochlorite (NaClO) in the removal of impurities, such as fat, grease, pectates, pectin and lignin. The processed PALF fibers were hydrolysed in sulfuric acid (H2SO4) at a concentration of 13.5 %, to obtain nano and microcrystals of cellulose. In the manufacture of biocomposite films, concentrations of cellulose, 0 %, 1 %, 3 %, 6 %, 9% and 12% were used as reinforcement to the matrices of PVA and PLA. The PVA was dissolved in distilled water at 80 ± 5 oC and the PLA was dissolved in dichloromethane at room temperature. The manufacture of biocompósitos in the form of films was carried out by "casting". Tests were carried out to study the water absorption by the films and mechanical test of resistance to traction according to ASTM D638-10 with a velocity of 50 mm/min.. Chi-square statistical test was used to check for the existence of significant differences in the level of 0.05: the lengths of the PALF, lengths of the nano and microcrystals of cellulose and the procedures used for the filtration using filter syringe of 0.2 μm or filtration and centrifugation. The hydrophilicity of biocompósitos was analysed by measuring the contact angle and the thickness of biocompósitos were compared as well as the results of tests of traction. Statistical T test - Student was also applied with the significance level (0.05). In biodegradation, Sturm test of standard D5209 was used. Nano and microcrystals of cellulose with lengths ranging from 7.33 nm to 186.17 nm were found. The PVA films showed average thicknesses of 0.153 μm and PLA 0.210 μm. There is a strong linear correlation directly proportional between the traction of the films of PVA and the concentration of cellulose in the films (composite) (0,7336), while the thickness of the film was correlated in 0.1404. Nano and microcrystals of cellulose and thickness together, correlated to 0.8740. While the correlation between the cellulose content and tensile strength was weak and inversely proportional (- 0,0057) and thickness in -0.2602, totaling -0,2659 in PLA films. This can be attributed to the nano and microcrystals of cellulose not fully adsorbed to the PLA matrix. In the comparison of the results of the traction of the two polymer matrices, the nano and microcrystals have helped in reducing the traction of the films (composite) of PLA. There was still the degradation of the film of PVA, within a period of 20 days, which was not seen in the PLA film, on the other hand, the observations made in the literature, the average time to start the degradation is above 60 days. What can be said that the films are biodegradable composites, with hydrophilicity and the nano and microcrystals of cellulose, contribute positively in the improvement of the results of polymer matrices used.