RELATIONSHIP AMONG EXTRACTIVES, LIGNIN AND HOLOCELLULOSE CONTENTS WITH PERFORMANCE INDEX OF SEVEN WOOD SPECIES USED FOR BOWS OF STRING INSTRUMENTS

In this paper we investigate the influence of extractives, lignin and holocellulose contents on performance index (PI) of seven woods used or tested for violin bows. Woods with higher values of this index (PI = root MOE/rho, where MOE is modulus of elasticity and rho is density) have a higher bending stiffness at a given mass, which can be related to bow wood quality. Extractive content was negatively correlated with PI in Caesalpinia echinata, Hanclroanthus sp. and Astronium lecointei. In C. echinata holocellulose was positively correlated with PI. These results need to be further explored with more samples and by testing additional wood properties. Although the chemical constituents could provide an indication of quality, it is not possible to establish appropriate woods for bows solely by examining their chemical constituents.

A study of ionic liquids for dissolution of sugarcane bagasse

Over the last decade, Ionic Liquids (ILs) have been used for the dissolution and derivatization of isolated cellulose. This ability of ILs is now sought for their application in the selective dissolution of cellulose from lignocellulosic biomass, for the manufacture of cellulosic ethanol. However, there are significant knowledge gaps in the understanding of the chemistry of the interaction of biomass and ILs. While imidazolium ILs have been used successfully to dissolve both isolated crystalline cellulose and components of lignocellulosic biomass, phosphonium ILs have not been sufficiently explored for the use in dissolution of lignocellulosic biomass. This thesis reports on the study of the chemistry of sugarcane bagasse with phosphonium ILs. Qualitative and quantitative measurements of biomass components dissolved in the phosphonium ionic liquids (ILs), trihexyltetradecylphosphonium chloride ([P66614]Cl) and tributylmethylphosphonium methylsulphate ([P4441]MeSO4) are obtained using attenuated total reflectance-Fourier Transform Infra Red (FTIR). Absorption bands related to cellulose, hemicelluloses and lignin dissolution monitored in situ in biomass-IL mixtures indicate lignin dissolution in both ILs and some holocellulose dissolution in the hydrophilic [P4441]MeSO4. The kinetics of lignin dissolution reported here indicate that while dissolution in the hydrophobic IL [P66614]Cl appears to follow an accepted mechanism of acid catalysed β-aryl ether cleavage, dissolution in the hydrophilic IL [P4441]MeSO4 does not appear to follow this mechanism and may not be followed by condensation reactions (initiated by reactive ketones). The quantitative measurement of lignin dissolution in phosphonium ILs based on absorbance at 1510 cm-1 has demonstrated utility and greater precision than the conventional Klason lignin method. The cleavage of lignin β-aryl ether bonds in sugarcane bagasse by the ionic liquid [P66614]Cl, in the presence of catalytic amounts of mineral acid. (ca. 0.4 %). The delignification process of bagasse is studied over a range of temperatures (120 °C to 150 °C) by monitoring the production of β-ketones (indicative of cleavage of β-aryl ethers) using FTIR spectroscopy and by compositional analysis of the undissolved fractions. Maximum delignification is obtained at 150 °C, with 52 % of lignin removed from the original lignin content of bagasse. No delignification is observed in the absence of acid which suggests that the reaction is acid catalysed with the IL solubilising the lignin fragments. The rate of delignification was significantly higher at 150 °C, suggesting that crossing the glass transition temperature of lignin effects greater freedom of rotation about the propanoid carbon-carbon bonds and leads to increased cleavage of β-aryl ethers. An attempt has been made to propose a probable mechanism of delignifcation of bagasse with the phosphonuim IL. All polymeric components of bagasse, a lignocellulosic biomass, dissolve in the hydrophilic ionic liquid (IL) tributylmethylphosphonium methylsulfate ([P4441]MeSO4) with and without a catalytic amount of acid (H2SO4, ca. 0.4 %). The presence of acid significantly increases the extent of dissolution of bagasse in [P4441]MeSO4 (by ca. 2.5 times under conditions used here). The dissolved fractions can be partially recovered by the addition of an antisolvent (water) and are significantly enriched in lignin. Unlike acid catalysed dissolution in the hydrophobic IL tetradecyltrihexylphosphonium chloride there is little evidence of cleavage of β-aryl ether bonds of lignin dissolving in [P4441]MeSO4 (with and without acid), but this mechanism may play some role in the acid catalysed dissolution. The XRD of the undissolved fractions suggests that the IL may selectively dissolve the amorphous cellulose component, leaving behind crystalline material.

ATR-FTIR measurement of biomass components in phosphonium ionic liquids

Qualitative and quantitative measurements of biomass components dissolved in the phosphonium ionic liquids (ILs), trihexyltetradecylphosphonium chloride ([P66614]Cl) and tributylmethylphosphonium methylsulphate ([P4441]MeSO 4), are obtained using attenuated total reflectance-FTIR. Absorption bands related to cellulose, hemicelluloses, and lignin dissolution monitored in situ in biomass-IL mixtures indicate lignin dissolution in both ILs and some holocellulose dissolution in the hydrophilic [P4441]MeSO 4. The kinetics of lignin dissolution reported here indicate that while dissolution in the hydrophobic IL [P66614]Cl appears to follow an accepted mechanism of acid catalyzed -aryl ether cleavage, dissolution in the hydrophilic IL [P4441]MeSO 4 does not appear to follow this mechanism and may not be followed by condensation reactions (initiated by reactive ketones). The measurement of lignin dissolution in phosphonium ILs based on absorbance at 1510 cm 1 has demonstrated utility. When coupled with the gravimetric Klason lignin method, ATR-FTIR study of reaction mixtures can lead to a better understanding of the delignification process. © 2012 Copyright Taylor and Francis Group, LLC.

Litter quality and its response to water level drawdown in boreal peatlands at plant species and community level

Changes in the structure of plant communities may have much more impact on ecosystem carbon (C) cycling than any phenotypic responses to environmental changes. We studied these impacts via the response of plant litter quality, at the level of species and community, to persistent water-level (WL) drawdown in peatlands. We studied three sites with different nutrient regimes, and water-level manipulations at two time scales. The parameters used to characterize litter quality included extractable substances, cellulose, holocellulose, composition of hemicellulose (neutral sugars, uronic acids), Klason lignin, CuO oxidation phenolic products, and concentrations of C and several nutrients. The litters formed four chemically distinct groups: non-graminoid foliar litters, graminoids, mosses and woody litters. Direct effects of WL drawdown on litter quality at the species level were overruled by indirect effects via changes in litter type composition. The pristine conditions were characterized by Sphagnum moss and graminoid litters. Short-term (years) responses of the litter inputs to WL drawdown were small. In longterm (decades), total litter inputs increased, due to increased tree litter inputs. Simultaneously, the litter type composition and its chemical quality at the community level greatly changed. The changes that we documented will strongly affect soil properties and C cycle of peatlands.

Aproveitamento da fibra do epicarpo do coco babaçu em compósito com matriz epóxi: estudo do efeito do tratamento da fibra

Nowadays the environmental issues are increasingly highlighted since the future of humanity is dependent on the actions taken by man. Major efforts are being expended in pursuit of knowledge and alternatives to promote sustainable development without compromising the environment. In recent years there has been a marked growth in the development of reinforced composite fiber plants, as an alternative for economic and ecological effects, especially in the substitution of synthetic materials such as reinforcement material in composites. In this current study the chemical- physical or (thermophysics )characteristics of the babassu coconut fiber, derived from the epicarp of the fruit (Orbignyda Phalerata), which the main constituents of the fiber: Klason lignin, insoluble, cellulose, holocellulose, hemicellulose and the content of ash and moisture will be determined. A study was conducted about the superficial modification of the fibers of the epicarp babassu coconut under the influence of chemical treatment by alkalinization, in an aqueous solution of NaOH to 2.5% (m/v) and to 5.0% to improve the compatibility matrix / reinforcement composite with epoxy matrix. The results of the changes occurred in staple fibers through the use of the techniques of thermogravimetric analyses (TG) and differential scanning calorimetry (DSC). The results found on thermal analysis on samples of fiber without chemical treatment (alkalinities), and on fiber samples treated by alkalinization show that the proposed chemical treatment increases the thermal stability of the fibers and provides a growth of the surface of area fibers, parameters that enhance adhesion fiber / composite. The findings were evaluated and compared with published results from other vegetable fibers, showing that the use of babassu coconut fibers has technical and economic potential for its use as reinforcement in composites

Análise química da madeira e casca de diferentes tipos de eucalipto antes e durante o cultivo de shiitake em toras

Avaliaram-se a composição química da madeira e da casca de sete espécies (E. saligna E. grandis, E. urophylla, E. camaldulensis, E. citriodora, E. paniculata e E. pellita) e três clones de eucalipto (híbridos de E. grandis x E. urophylla), antes e durante o cultivo das linhagens LE-95/01 e LE-96/18 de shiitake (Lentinula edodes), em toras. Cada linhagem de shiitake foi inoculada em nove toras de cada tipo de eucalipto com 1 m de comprimento e 9 a 14 cm de diâmetro. Assim, o delineamento experimental foi inteiramente casualizado, com 20 tratamentos e nove repetições, sendo cada repetição correspondente a uma tora. As toras foram mantidas em estufa climatizada, com temperatura de 25 ºC ± 5 e umidade relativa do ar entre 60-80%, durante 12 meses. Para a determinação da composição química da madeira, analisaram-se cunhas de discos e cascas de eucalipto recém-cortadas (sem inoculação das linhagens de L. edodes) e cunhas de discos e cascas retirados de toras já inoculadas com as linhagens de L. edodes após oito meses de incubação. Os resultados mostraram diferenças nos teores de holocelulose, lignina e extrativos totais na madeira e casca após o corte e depois de oito meses de incubação nas espécies e clones de eucalipto; o maior índice de decomposição da holocelulose na madeira, ao longo do tempo, ocorreu no E. saligna (5,5%), indicando, assim, ser o mais favorável para o desenvolvimento micelial do L. edodes. Já na casca aconteceu no clone 24 (22,2%). O E. camaldulensis apresentou o maior índice de decomposição da lignina na madeira (6,8%), ao longo do tempo. Já na casca, entre os eucaliptos testados, o E. grandis sofreu a maior decomposição de lignina (21,9%); o L. edodes degradou muito mais a holocelulose e lignina da casca que da madeira, tornando evidente a importância da casca; a casca da maioria dos tipos de eucaliptos apresentou menor teor de holocelulose, maior teor de extrativos totais e teores de lignina semelhantes ou superiores quando comparados com a madeira. O fator tipo de eucalipto (espécies e clones) teve maior efeito que o fator linhagem de L. edodes na degradação da holocelulose e lignina.

Biodegradation of Coir and Sisal Applied in the Automotive Industry

This paper discusses the results of biodegradability tests of natural fibers used by the automotive industry, namely: coir, coir with latex, and sisal. The biodegradation of coir, coir with latex, and of sisal fibers was determined by monitoring the production of carbon dioxide (CO(2)) (IBAMA-E.1.1.2, 1988) and fungal growth (DIN 53739, 1984). The contents of total extractives, lignin, holocellulose, ashes, carbon, nitrogen and hydrogen of the fibers under study were determined in order to ascertain their actual content and to understand the results of the biodegradation tests. The production of CO(2) indicated low biodegradation, i.e., about 10% in mass, for all the materials after 45 days of testing; in other words, no material inhibited glucose degradation. However, the percentage of sisal fiber degradation was fourfold higher than that of coir with latex in the same period of aging. The fungal growth test showed a higher growth rate on sisal fibers, followed by coir without latex. In the case of coir with latex, we believe the fungal growth was not intense, because natural latex produces a bactericide or fungicide for its preservation during bleeding [1]. An evaluation of the materials after 90 days of aging tests revealed breaking of the fibers, particularly sisal and coir without latex, indicating fungal attack and biodegradation processes.

Chemical properties and decay resistance of eucalyptus grandis wood from steamed logs

The objective of this study was evaluate the effect of the log steaming on the chemical properties and decay resistance of Eucalyptus grandis wood. Logs with diameter between 20 and 22 cm were studied. Half of logs were kept in its on original condition, and the other half was steamed at 90°C for 13 hours. The holocellulosc, Klason lignin, total extractives content and the weight loss caused by the decay fungus Pycnoporus sanguineous were characterized. The results showed that the log steaming of E. grandis wood cause: (l)a significantly decreased in holocellulose content; (2) an increase of 4.8% and 4.4% in total extractives and lignin content, respectively; and (3) a decrease in its durability against the decay fungus P. sanguineus in order of 13.03%. Copyright © (2012) by WCTE 2012 Committee.

Caracterização química, física e térmica de pellets de madeira produzidos no Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Crescimento e qualidade da madeira de plantas jovens de híbridos de Eucalyptus grandis x E. urophylla

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Estudo comparativo da madeira e polpação de Eucalyptus urophylla e do híbrido E. urophylla x E. grandis em dois modelos silviculturais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determinação das propriedades físicas e químicas da madeira de Hevea brasiliensis em relação ao painel de extração de látex

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dimensões de cavacos industriais de eucalipto e relações com polpação, resistência e morfologia de fibras na polpa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da vaporização na madeira de Eucalyptus grandis sobre as suas propriedades químicas e resistência natural a fungos e cupins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da biodegradação das fibras de coco e de sisal visando às aplicações na indústria automotiva

Pós-graduação em Agronomia (Energia na Agricultura) - FCA