Piassava Fiber Research Articles

Evaluation of Surface Treatment Effects on the Tensile Strength of Piassava (Attalea Funifera) Fibers Using the Weibull Distribution

The effect of several surface treatments on the tensile strength of piassava fibers is discussed in terms of the Weibull statistical distribution. It is shown that the Weibull modulus can be used as an indicative parameter of the degree of surface structural modifications caused by the surface treatments, refining the results obtained by the LSD statistical test. SEM analysis was used to independently characterize the fiber surface structural changes caused by the treatments and corroborates the results inferred from the Weibull modulus.

The use of piassava fibers (Attalea funifera) in the preparation of activated carbon

The piassava fiber, residue of the broom industry, was used as precursor for the preparation of activated carbons (AC). AC were prepared by chemical activation with zinc chloride (AC ZnCl2) or phosphoric acid (AC H3PO4) and by physical activation with carbon dioxide (AC CO2) or water vapor (AC H2O). These materials were characterized by adsorption/desorption of N2 to determine the BET areas, elemental analysis (CHN), thermogravimetric analysis (TG, DTA) and scanning electron microscopy (SEM). The carbons were tested with respect to their adsorption capacity of methylene blue, reactive red, phenol and metallic ions (Cr+6, Cu+2 and Zn+2). AC ZnCl2 presented the highest surface area (1190m2g−1) and AC H3PO4, the largest pore volume (0.543cm3g−1). AC ZnCl2 was more efficient in the adsorption of methylene blue, Cr+6 and Cu+2 ions. AC H2O was the better adsorbent for phenol, while AC CO2 was better for Zn+2 ions.

Gelatin/piassava composites treated by electron beam radiation

Piassava (Attalea funifera Mart) fiber has been investigated as reinforcement for polymer composites with potential for practical applications. The purpose of the present work was to assess the behavior of specimens of piassava fiber and gelatin irradiated with electron beam at different doses and percentage. The piassava/gelatin specimens were made with 5 and 10% (w/w) piassava fiber, gelatin 25% (w/w), glycerin as plasticizer and acrylamide as copolymer. The samples were irradiated up to 40 kGy using an electron beam accelerator, at room temperature in presence of air. Preliminary results showed mechanical properties enhancement with the increase in radiation dose.

Tensile behavior of lignocellulosic fiber reinforced polymer composites: Part I piassava/epoxy

The fibers extracted from the piassava palm tree, scientifically known as Attalea funifera, are among the stiffest lignocellulosic fibers being considered for polymer composite reinforcement. Characterization of piassava composites have been carried out for different polymeric matrices and mechanical tests. In this work the tensile properties of DGEBA/TETA epoxy matrix composites reinforced with up to 30% in volume of continuous and aligned piassava fibers were evaluated. Tensile specimens post-cured at 60ºC for 4 hours were room temperature tested and the corresponding fracture analyzed by scanning electrons microscopy. The results showed a decrease in both the tensile strength and the elastic modulus of the composites up to 30% with an increase at 40% of piassava fibers to values above those of the pure epoxy. The fracture analysis revealed a weak fiber/matrix interface, which could account for the comparative low performance of these composite in tensile tests up to 30% of volume fraction. The relatively large amount of stronger piassava fibers accounts for the better performance of the composite with 40% in volume fraction.

Properties and Structure of Attalea funifera Piassava Fibers for Composite Reinforcement – A Critical Discussion

Results on morphological, structural, thermal, tensile mechanical and chemical characterization of Attalea funifera piassava fiber have been presented by different research groups. In particular, a paper by Elzubair et al. (2007) showed apparent differences from values reported by previous works. These results needed to be complemented in terms of information required for the use of this natural fiber as a polymer composite reinforcement. In this work, a critical discussion on the differences reported so far is presented. A complementary information on the properties and structural characteristics of Attalea funifera fiber with findings related to its application as a composite reinforcement is also provided.

Morphological, Structural, Thermal and Mechanical Characterization of Piassava Fibers

For the purpose of evaluating the suitability of piassava fiber as reinforcement of polymer matrix (recycled polyethylene), we carried out extensive characterization of morphological, structural, thermal, and mechanical properties of two species of piassava fibers, namely Leopoldinia piassaba (Amazon, Brazil) and Attalea funifera (Bahia, Brazil). Scanning electron microscopy images revealed that each fiber is essentially a composite in which rigid cellulose microfibrils are embedded in a soft lignin and hemicellulose matrix. In addition, the tubular microfibrils are helically wound along the fiber axis forming ultimate hollow cells. An irregularly dimensioned mass, composed mainly of silica, appears on the surface of each fiber. The crystallinity of L. piassaba is found to be inferior to that of A. funifera. On the other hand, thermal analysis shows that both species start to decompose at approximately similar temperature (∼265°C), and that the moisture content in each is approximately 4 to 5%. The mechanical properties correlate well with the fiber diameter. Finally, the L. piassaba, as compared with A. funifera, is softer and more ductile.

Substratos alternativos ao xaxim e adubação de plantas de orquídea na fase de aclimatização

Objetivou-se estudar substratos e adubação em plantas de orquídea da espécie C. loddgesii "Alba" x C. loddgesii "Atibaia". Plantas oriundas de cultivo in vitro foram transplantadas para bandejas coletivas contendo pó de xaxim e aclimatizadas em casa de vegetação. Após seis meses, quando as plantas tinham de 3,0 a 5,0cm de comprimento, foram transferidas para bandejas de plástico com 24 células de 150cm³ cada contendo os substratos brita no 0, casca de arroz carbonizada (CAC), xaxim desfibrado e fibra de piaçava e submetidas a adubações semanais com Biofert Plus® (5,0mL L-1), Dyna-Grow® (2,5mL L-1) e formulação elaborada. Após 12 meses, verificou-se que os melhores substratos para plantas da orquídea C. loddgesii "Alba" x C. loddgesii "Atibaia" são casca de arroz carbonizada e fibra de piaçava, e melhores respostas à adubação são obtidas com o adubo foliar Biofert Plus®.

Dynamic Mechanical Behavior of Piassava Fibers (Attalea funifera) Reinforced Polyester Composites

This work compares the dynamic mechanical behavior of piassava fiber–reinforced polyester composites with the behavior of the neat resin matrix. The results obtained confirm previous data showing that the interface of piassava/polyester composites is stronger than the usual interfaces found when untreated lignocellulosic fibers are incorporated into common polyester matrices. This behavior was attributed to silica-rich protrusions found at the fibers' surface that aid to anchor the resin matrix and increase the stress transfer at the fiber–matrix interface.

Tenacidade ao entalhe por impacto Charpy de compósitos de poliéster reforçados com fibras de piaçava

Fibras rígidas de piaçava do tipo Attalea funifera Mart vêm sendo recentemente investigadas como reforços efetivos para compósitos de matriz polimérica. Os trabalhos até agora realizados nestes compósitos mostraram um razoável aumento na resistência mecânica com a proporção de fibra. Como algumas possíveis aplicações para compósitos de piaçava demandariam resistência ao impacto, o objetivo do presente trabalho foi realizar um estudo da tenacidade ao entalhe, medida em pêndulo de impacto de compósitos com matriz poliéster reforçada com fibras rígidas e alinhadas de piaçava. Corpos de prova padronizados de compósitos com até 40% de fibras contínuas de piaçava foram avaliados por meio de ensaios Charpy e suas microestruturas na fratura investigadas através de microscopia eletrônica de varredura. Os resultados obtidos revelaram que compósitos de piaçava apresentam tenacidade ao entalhe comparativamente superior ao de outros compósitos poliméricos de fibras naturais.

Tensile mechanical properties, morphological aspects and chemical characterization of piassava (Attalea funifera) fibers

The tensile mechanical properties of piassava fibers, as well as their chemical composition and morphological aspects, are reported. The values obtained showed that piassava has a mechanical behavior and chemical composition comparable to that of coir fibers. The difficulties related with a reliable way of measuring the true elastic modulus of these slender fibers are discussed and a simple correction of the experimental data is presented. As main characteristic surface features piassava fibers present a well arranged pattern of silicon rich star-like protrusions. Its chemical composition reveals that piassava are lignin rich fibers, 48.4 wt%. X-ray diffraction showed that cellulose I is their main crystalline constituent. Their thermal degradation begins at 225 °C, and the whole thermal degradation behavior of piassava fibers has many aspects, like the initial water loss and the content of residues, close to that shown by pure lignin.

Effect of drying, molding pressure, and strain rate on the flexural mechanical behavior of piassava ( Attalea funifera Mart) fiber–polyester composites

The flexural strength of piassava-polyester composites was evaluated as a function of the molding force, strain rate and drying condition of the fibers. Composites with as-received fibers and with pre-dried fibers were fabricated, with mass fraction of fibers ranging from 0.20 to 0.40. The pre-drying of the fibers was shown to be the most relevant variable. Reduction of absorbed water before the incorporation of the fibers to the polyester matrix strongly affected the wetting of the fiber by the polymeric matrix, enhancing the fiber to matrix interaction. The composites manufactured with the pre-dried fibers show better flexural strength. Their behavior was independent of the molding pressure. The flexural strength of the composites decreased with the increase of the strain rate, but only minor variations were measured under the range of strain rates analyzed. The composites with the higher fiber loading, and pre-dried fibers, showed flexural strength values similar to the higher values reported for other lignocellulosic fiber-reinforced composites.

Application of Spectroscopic Methods for Characterization of the Composition of Piassava

Abstract Abstract Spectroscopic methods—infrared absorption, atomic emission spectroscopy, and x-ray diffraction—were used for the characterization of the organic and inorganic composition and structure of piassava. The analysis of the infrared spectra revealed that pias-sava fibers consist mainly of cellulose, lignin, and hemicellulose, and that this chemical composition is similar to that of jute. The infrared spectra together with the x-ray diffraction of the ash showed that it consists of sulfate, silicate, and carbonate compounds. The semiquantitative atomic emission analysis showed that the inorganic part contains major amounts of P, Mg, Na, Ca. and Si; and trace amounts, of Mn, Al, and K.