Morphological and crystalline characterization of NaOH and NaOCl treated Agave americana L. fiber

Oudiani, Asma El; Chaabouni, Yassine; Msahli, Slah; Sakli, Faouzi

doi:10.1016/j.indcrop.2011.09.012

Cited by 124 publications

(56 citation statements)

References 44 publications

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“…A modificação ocasionada por esse tratamento é o rompimento da ligação de hidrogênio no grupo hidroxila (OH) presente na estrutura da fibra, aumentando assim a rugosidade superficial [20,21] . Este tratamento remove certa quantidade de lignina, cera e óleos que recobrem a superfície externa da parede celular da fibra, despolimerizando a celulose amorfa, removendo grande parte da hemicelulose das fibras.…”

Section: -Efeito Do Tratamento Alcalino De Fibras De Curauá Sobre As unclassified

Efeito do tratamento alcalino de fibras de curauá sobre as propriedades de compósitos de matriz biodegradável

Beltrami¹,

Scienza²,

Zattera³

2014

Polímeros

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Resumo: Neste trabalho avaliou-se a influência do tratamento alcalino das fibras de curauá, nas concentrações de 1, 5 e 10%(m/v) de NaOH, nas propriedades dos compósitos com matriz de PHBV e 20% m/m de fibras de curauá. Os compósitos foram moldados por extrusão e injeção e avaliadas suas as propriedades morfológicas, térmicas e mecânicas. Os resultados de FTIR mostraram que o tratamento alcalino promoveu modificações na estrutura das fibras de curauá, comprovadas pela remoção da hemicelulose e da lignina, evidenciadas pela ausência das bandas típicas destes compostos. Nos compósitos com fibras de curauá tratadas com solução de NaOH na concentração de 5% apresentaram um aumento de 30% na resistência à flexão e 12% na resistência ao impacto, quando comparados aos compósitos com fibras sem tratamento. Estes resultados indicam que o tratamento alcalino promoveu uma melhoria na adesão das fibras na matriz, o que melhorou significativamente as propriedades mecânicas dos compósitos. Palavras-chave: Compósitos, PHBV, fibras de curauá, tratamento alcalino. Effect of the Alkaline Treatments of Curauá Fiber on the Properties of Biodegradable Matrix CompositesAbstract: This study investigate the influence of alkaline treatment applied to Curauá fibers, at concentrations of 1, 5 and 10% (w/v) NaOH, on the properties of the composite of PHBV matrix with 20 wt % Curauá fiber. The composites were molded by extrusion and injection and their morphological, thermal and mechanical properties were evaluated. The results showed that alkali treatment caused modifications in the structure of the Curauá fibers by the removal of hemicellulose and lignin, as evidenced by the absence of the typical bands of these compounds in FTIR analysis. It was found an increase of 30% in flexural strength and 12% in impact resistance for the composites with fibers treated in 5% NaOH solution, in relation to composites with fibers without treatment. These results indicate that the alkaline treatment promoted an improvement in the adhesion of the fibers to the matrix, which significantly improved the mechanical properties of the composites. However, concentrations of NaOH solution different from 5% may have a deleterious effect on the mechanical properties of the fibers and composites.

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Section: -Efeito Do Tratamento Alcalino De Fibras De Curauá Sobre As unclassified

Efeito do tratamento alcalino de fibras de curauá sobre as propriedades de compósitos de matriz biodegradável

Beltrami¹,

Scienza²,

Zattera³

2014

Polímeros

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“…Estos tratamientos también permiten eliminar impurezas como las ceras, pectinas y sales minerales incrementando su área superficial (Saucedo et al, 2010;Ben Sghaier et al, 2012;Rosli et al, 2013).…”

Section: Introductionunclassified

“…For example, when the process of maceration is applied together with the use of acid-alkaline treatments, the separation of hemicellulose and lignin fibers occurs, which also improves the fibers in regards to their thermal stability and tensile strength, necessary factors for the elaboration of composites. These treatments also help the elimination of impurities such as waxes, pectin and mineral salts increasing surface area (Saucedo et al, 2010;Sghaier et al, 2012;Rosli et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Aislamiento y caracterización de celulosas obtenidas de fibras de Agave salmiana aplicando dos métodos de extracción ácido-alcali

Naranjo¹,

Alamilla‐Beltrán²,

Gutiérrez‐López³

et al. 2017

Remexca

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ResumenPara aprovechar las pencas de agaves (A. salmiana) una vez que se retiran de la piña de la planta, se obtuvieron fibras. Las hojas fueron tratadas con hidrólisis ácida (HCl) e hidrólisis alcalina (NaOH), usando presión de 1.1 kg/cm 2 (FACT ácido-álcali con presión), a 121 °C por 4 h y otro tratamiento a presión atmosférica con reflujo (FACT ácido-álcali sin presión). Se determinó el porcentaje de celulosa y lignina, así como los cambios fisicoquímicos por medio de calorimetría diferencial de barrido (DSC), termogravimetría (TG), Difracción de rayos X (DRX), Espectroscopia infrarroja (IR) y Microscopia electrónica de barrido ambiental (MEB). El mayor contenido de celulosa (79.95%) se obtuvo para el tratamiento FACT ácido-álcali sin presión, presentando también una mayor cristalinidad (50.07). La microestructura mostró que el tratamiento FACT ácido-álcali con presión mostró más espacios vacíos, esto debido a la degradación de las fibras, lo cual se asocia a una pérdida de celulosa. Ambos tratamientos afectaron la estructura y composición de las fibras de agave.Palabras clave: celulosa, fibras de agave, lignina, tratamiento ácido-base sin presión, tratamiento ácido-base con presión. AbstractFibers were obtained in order to make use of the agave leaves (A. salmiana) once the heart of the plant was removed. The leaves were treated with acid hydrolysis (HCl) and alkaline hydrolysis (NaOH), using a pressure of 1

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“…Alkaline solution can dissolve lignin so that cellulose is exposed as follows [30]: fiber-OH + NaOH → fiber-O-Na + + H2O (2) After alkaline followed by ionic liquid pretreatment (NaOH+IL), the peak (002) declined significantly, and the peak (101) almost diminished, relating to the change of the substrate from cellulose I to cellulose II, which has a low crystallinity (amorphous structure). There was also a shift of the peak, approximately 0.50 o to the right, which meant that the lattice expanded after pretreatment.…”

Section: Characterization Of Pretreated Coconut Coir Dustmentioning

confidence: 99%

Preparation of Reducing Sugar Hydrolyzed from High-Lignin Coconut Coir Dust Pretreated by the Recycled Ionic Liquid [mmim][dmp] and Combination with Alkaline

Sangian

Kristian

Rahma

et al. 2014

Bull. Chem. React. Eng. Catal.

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This study aims to produce reducing sugar hydrolyzed from substrate, coconut coir dust pretreated by recycled ionic liquid and its combination with alkaline. The 1H NMR and FTIR were performed to ver-ify the synthesized ionic liquid methylmethylimidazolium dimethyl phosphate ([mmim][dmp]). The structure of pretreated substrates was analyzed by XRD measurement. The used ionic liquid was recy-cled twice to re-employ for substrate pretreatment. The treated- and untreated-coconut coir dust were hydrolyzed into sugars using pure cellulase. The reaction, which called an enzymatic hydrolysis, was conducted at 60 °C, pH 3, for 48 h. The yields of sugar hydrolyzed from fresh IL-pretreated, 1R*IL-pretreated and 2R*IL-pretreated substrates were of 0.19, 0.15 and 0.15 g sugar / g cellu-lose+hemicellulose, respectively. Pretreatment with NaOH or the combination of NaOH+IL resulted in yields of reducing sugars of 0.25, 0.28 g/g, respectively. When alkaline combined with the recycled ionic liquids, NaOH+1R*IL, NaOH+2R*IL in the pretreatment, the yields of sugar were relatively similar to those obtained using alkaline followed by fresh ionic liquid. If the mixture enzymes, cellu-lase+xylanase, used to liberate sugars from fresh IL-pretreated, or recycled IL-pretreated substrates, the amount of sugar (concentration or yield) increased slightly compared to that employing a single cel-lulase. These findings showed that recycled IL pretreatment of the high-lignin lignocellulose, coconut coir dust, is a new prospect for the economical manufacture of fermentable sugars and biofuel in the coming years. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

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Morphological and crystalline characterization of NaOH and NaOCl treated Agave americana L. fiber

Cited by 124 publications

References 44 publications

Efeito do tratamento alcalino de fibras de curauá sobre as propriedades de compósitos de matriz biodegradável

Efeito do tratamento alcalino de fibras de curauá sobre as propriedades de compósitos de matriz biodegradável

Aislamiento y caracterización de celulosas obtenidas de fibras de Agave salmiana aplicando dos métodos de extracción ácido-alcali

Preparation of Reducing Sugar Hydrolyzed from High-Lignin Coconut Coir Dust Pretreated by the Recycled Ionic Liquid [mmim][dmp] and Combination with Alkaline

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