Infra-red spectroscopic study of lignins

Nada, A. M. A.; El-Sakhawy, Mohamed; Kamel, Samir

doi:10.1016/s0141-3910(97)00072-4

Cited by 92 publications

(43 citation statements)

References 6 publications

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“…As ligninas Kraft são subprodutos do licor negro (Wallberg et al, 2005), produzido na polpação Kraft, sofrem hidrólise parcial de grupos OH fenólicos, o que provoca um aumento dos valores médios de absorbância relativa de grupos hidroxila e apresentam elevado teor de grupos OH fenólicos e baixo OCH 3 (Nada et al, 1998).…”

Section: Resultsunclassified

Atributos químicos do solo e lixiviação de compostos fenólicos após adição de resíduo sólido alcalino

Branco

Silveira

Campos

et al. 2013

Rev. bras. eng. agríc. ambient.

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RESUMOA utilização de resíduos alcalinos da indústria de papel e celulose (DREGS) na agricultura como corretivo de acidez do solo, vem sendo amplamente empregada como alternativa de descarte no solo de forma a reduzir o impacto ambiental. Objetivou-se, com este trabalho, determinar a influência da aplicação do dregs, rejeito da indústria de papel e celulose, nos atributos químicos do solo e na lixiviação de compostos fenólicos. As unidades experimentais foram constituídas por colunas de lixiviação preenchidas com solo incorporado com dregs nas doses de 0,0; 2,5; 5,0 e 10,0 g kg -1 . Chemical attributes of soil and leaching of phenolic compounds after addition of alkaline solid residue ABSTRACT The use of alkaline residues from pulp and paper industry (´dregs´) in agriculture as a corrective of soil acidity is being widely used as an alternative of ground disposal in order to reduce the environmental impact. The objective of this study was to determine the influence of application of the 'dregs', waste from pulp and paper industry, in soil chemical properties and leaching of phenolic compounds. The experimental units consisted of leaching columns filled with soil incorporated with 'dregs' at doses of 0, 2.5, 5.0 and 10.0 g kg -1 . Chemical analysis were performed in these soils, a Humic Camibissolo and a Typic Quartzipsamment soils, tests of solubilization of phenolic compounds and leaching tests were also carried out to determine the total content of phenolic compounds present in the leachate. The use of the 'dregs' modified the chemical attributes of the Humic Cambisol and Typic Quartzipsamment. The results obtained in the analysis of the leachate showed that the application of the 'dregs' led to an increase of compounds above the maximum allowed by law, which is 0,01 mg L -1 (ANBR, 2004a) and 0,5 mg L -1 (CONAMA, 2008).

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Section: Resultsunclassified

Atributos químicos do solo e lixiviação de compostos fenólicos após adição de resíduo sólido alcalino

Branco

Silveira

Campos

et al. 2013

Rev. bras. eng. agríc. ambient.

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“…3), which is indicative of dehydration and dehydrogenation reactions. This is also evidenced by the drastic decline in the absorptions at 1082 and 1026 cm -1 (C-O stretch in secondary and primary alcohols, respectively) (Hergert 1960;Nada et al 1998). Peaks at 1743 (C=O) and 766 cm -1 (O-C=O in-plane deformation) exhibited characteristics of esters and decreased with increasing temperature.…”

Section: Xylanmentioning

confidence: 90%

“…Accordingly, this absorption peak was attributed to both types of vibrations (Faix 1991;Pandey 1999), although it was believed to be mostly due to C-H deformation vibrations in methoxy groups. The characteristic absorption of phenolic O-H deformation vibrations at 1215 cm -1 (Nada et al 1998) also decreased with increasing temperature. Correspondingly, the decline of other characteristic phenolic absorptions at 1369 (Nada et al 1998) and 1327 cm -1 (associated with ortho methoxy) (Bermello et al 2002) are evidence of the decomposition of phenolic groups.…”

Section: Xylanmentioning

confidence: 91%

“…The characteristic absorption of phenolic O-H deformation vibrations at 1215 cm -1 (Nada et al 1998) also decreased with increasing temperature. Correspondingly, the decline of other characteristic phenolic absorptions at 1369 (Nada et al 1998) and 1327 cm -1 (associated with ortho methoxy) (Bermello et al 2002) are evidence of the decomposition of phenolic groups. Nevertheless, assignments of the peaks at 1369 and 1327 cm -1 was difficult in that the former was considered an aliphatic C-H stretch in CH3 but not in methoxy (Faix 1991), while the latter was assigned to C-H bending of the methyl group in methoxy (Briggs et al 1957).…”

Section: Xylanmentioning

confidence: 91%

“…Furthermore, dehydration/dehydrogenation resulted in the disappearance of the peak at 1660 cm -1 , which was attributed to the intra-molecular hydrogen-bond in carboxylic acid. Meanwhile, decreases in absorption peaks at 1462, 1451, and 1419 cm -1 , characteristic of asymmetric and symmetric CH3 deformation in methoxy groups (Åkerholm and Salmén 2001;Nada et al 1998), demonstrated the decomposition of the Caryl-O-CH3 group, the weakest bond in a guaiacol unit (Masuku et al 1988). However, interpretation of the spectra was not straightforward because it is possible that the absorption peak at 1419 cm -1 was related to aromatic skeletal vibrations (Boeriu et al 2004).…”

Section: Xylanmentioning

confidence: 99%

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TGA-FTIR Analysis of Torrefaction of Lignocellulosic Components (cellulose, xylan, lignin) in Isothermal Conditions over a Wide Range of Time Durations

Lv¹,

Perré²,

Perré³

2015

BioResources

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This study investigated chemical decomposition of lignocellulosic components in the course of torrefaction under isothermal conditions for durations up to 5 hours. The goal was a better understanding of the behaviour of biomass, at both short and long residence times, which is important for innovation in the chemical and bioenergy industries. Gaseous and solid-phase decomposition products of cellulose, xylan, and two lignins, were studied following torrefaction at three temperatures (220, 250, and 280 °C) for a continuous recording of mass loss and emission of volatiles over 5 hours. Two decomposition stages were revealed for xylan, with a notable release of CO that increased with treatment temperature. 4-O-methyl glucurono-units on the side chains of xylan degraded first, and acetyl groups and macromolecule fragments accounted for the second degradation, starting at 250 °C. The primary production of acetic acid occurred at 280 °C. For the two lignins, decomposition reactions predominated at lower temperatures, while rearrangement prevailed at 280 °C. The emission of phenol was a clear distinction between the two. Cellulose was thermally stable at short times under all treatments, but it decomposed dramatically afterwards, especially at 280 °C.

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Properties and structure of PVP–lignin “blend films”

Liu

Xiao

Liang³

2005

J of Applied Polymer Sci

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Blend films of poly (4-vinylpyridine) and lignin were prepared by the casting method. Their structure and properties were studied by Fourier transform infrared (FTIR), wide-angle X-ray diffraction (WXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). The IR spectra of the blend films indicated that hydrogen-bonding interaction occurred between poly (4-vinylpyridine) and lignin. The glass transition temperature of these blends increased with the increase of lignin content, which indicated that these blends were able to form a miscible phase due to the formation of intermolecular hydrogen bonding between the hydroxyl of lignin and the pyridine ring of poly (4-vinylpyridine). The thermostability of these blends decreased with the increase of lignin content. Initially, an appreciable increase in the measured tensile strength was achieved with a lignin content of 15%, at which the maximum value of 33.03 MPa tensile strength was reached. At a 10% lignin incorporation level, the blend film exhibited a maximum value of 9.03% strain. When the threshold in lignin content for blend films exceeded that limit of 10% lignin, the strain behavior of these blend films deteriorated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci

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Infra-red spectroscopic study of lignins

Cited by 92 publications

References 6 publications

Atributos químicos do solo e lixiviação de compostos fenólicos após adição de resíduo sólido alcalino

Atributos químicos do solo e lixiviação de compostos fenólicos após adição de resíduo sólido alcalino

TGA-FTIR Analysis of Torrefaction of Lignocellulosic Components (cellulose, xylan, lignin) in Isothermal Conditions over a Wide Range of Time Durations

Properties and structure of PVP–lignin “blend films”

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