Contribution of xylan to the brightness development and stability in the final ECF bleaching of eucalypt (<i>Eucalyptus globulus</i> Labill.) kraft pulp

Loureiro, Pedro E. G.; Sousa, Joana I.T.; Carvalho, M. G.; Evtuguin, Dmitry V.

doi:10.1515/hf-2012-0185

Cited by 7 publications

(8 citation statements)

References 20 publications

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“…Lignin residues, carbonyl groups, xylan, hexenuronic acid (HexA) groups, and transition metal ions are involved in the yellowing reactions1314. Residual lignin, the products of polysaccharide chain thermal decay and xylan are the main (although debatable) causes for heat-induced yellowing of chemical pulps15. Light-induced yellowing is principally associated with lignin-rich pulps (i.e., HYP).…”

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confidence: 99%

Xylanase Treatment Suppresses Light- and Heat-Induced Yellowing of Pulp

Zhang

Wang

et al. 2016

Sci Rep

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Xylanase is commonly applied in pulp and paper industries to ease cost-related and environmental pressures. The effect of xylanase treatment on pulp bleaching is well-established, however, few studies were conducted on the effects of xylanase treatment in pulp yellowing, especially the mechanism of pulp yellowing inhibition by xylanase treatment. In this study, pure xylanase (EC 3.2.1.8) was applied to treat wheat straw chemical pulp (CP) and poplar chemi-thermo-mechanical pulp (CTMP) to determine their effects on pulp brightness and on light- and heat-induced yellowing. The xylanase treatment decreased the post-color number of the pulps during light- and heat-induced yellowing. However, differences were observed in the yellowing inhibition between the wheat straw CP and poplar CTMP. The changes in chemical components of pulps after the xylanase treatment, for example, lignin, hemicellulose, and HexA contents, and analysis of UV–vis absorption spectra and Fourier transform infrared-attenuated total reflectance spectrum were used to explore the pulp yellowing inhibition causes by the xylanase treatment.

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confidence: 99%

Xylanase Treatment Suppresses Light- and Heat-Induced Yellowing of Pulp

Zhang

Wang

et al. 2016

Sci Rep

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“…However, in the DEDXD sequence, for the same chlorine dioxide load in the final D stage, higher brightness and lower reversion were achieved, when compared with the DEDD sequence. Interference of xylanase with structures responsible for the pulp color and brightness reversion may be inferred . The extraction of stabilised quinones chromophoric structures has been mentioned as a result of the xylanase treatment .…”

Section: Resultsmentioning

confidence: 99%

“…Recently it was found that a final D stage in the DEDD sequence caused new unsaturated structures in xylan, which were much less abundant in pulp bleached by a final P stage in the DEDP sequence . The important role of xylan as a source of chromophores and their effect on brightness development and stability of bleached eucalypt pulps have been evidenced . Xylan in eucalypt kraft pulp is structurally associated with residual lignin, which is the main source of chromophore structures .…”

Section: Introductionmentioning

confidence: 99%

Enzymatic treatment applied as a final stage in E. globulus kraft pulp bleaching

Sousa

Moura

Evtuguin

et al. 2015

J of Chemical Tech & Biotech

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BACKGROUND: Brightness stability of bleached chemical pulps is often associated with the final bleaching stages that should provide the removal of chromogenic species responsible for brightness reversion without compromising the papermaking potential. Aiming at promoting higher brightness stability, a partially bleached Eucalyptus globulus pulp (DED) of c. 88% ISO brightness was involved in a study of a final enzymatic stage (X) alternative to conventional chlorine dioxide (D) and hydrogen peroxide (P) bleaching stages (DEDX vs. DEDD and DEDX vs. DEDP). X stage was also applied before and after the final P or D stages (DEDDX/DEDXD and DEDPX/DEDXP) to produce high brightness pulps (c. 91%).

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“…Taking into account the fact that all materials presented similar lignin contents (between 1.2% and 1.6%), the high brightness of the E-MFC film could be related to its lower xylan content (19.1%). In addition, xylan-lignin complexes are a source of residual poly-conjugates chromophores [51].…”

Section: Optical and Mechanical Propertiesmentioning

confidence: 99%

Production of Microfibrillated Cellulose from Fast-Growing Poplar and Olive Tree Pruning by Physical Pretreatment

et al. 2021

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Motivated by the negative impact of fossil fuel consumption on the environment, the need arises to produce materials and energy from renewable sources. Cellulose, the main biopolymer on Earth, plays a key role in this context, serving as a platform for the development of biofuels, chemicals and novel materials. Among the latter, micro- and nanocellulose have been receiving increasing attention in the last few years. Their many attractive properties, i.e., thermal stability, high mechanical resistance, barrier properties, lightweight, optical transparency and ease of chemical modification, allow their use in a wide range of applications, such as paper or polymer reinforcement, packaging, construction, membranes, bioplastics, bioengineering, optics and electronics. In view of the increasing demand for traditional wood pulp (e.g., obtained from eucalypt, birch, pine, spruce) for micro/nanocellulose production, dedicated crops and agricultural residues can be interesting as raw materials for this purpose. This work aims at achieving microfibrillated cellulose production from fast-growing poplar and olive tree pruning using physical pretreatment (PFI refining) before the microfibrillation stage. Both raw materials yielded microfibrillated cellulose with similar properties to that obtained from a commercial industrial eucalypt pulp, producing films with high mechanical properties and low wettability. According to these properties, different applications for cellulose microfibers suspensions and films are discussed.

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Contribution of xylan to the brightness development and stability in the final ECF bleaching of eucalypt (Eucalyptus globulus Labill.) kraft pulp

Cited by 7 publications

References 20 publications

Xylanase Treatment Suppresses Light- and Heat-Induced Yellowing of Pulp

Xylanase Treatment Suppresses Light- and Heat-Induced Yellowing of Pulp

Enzymatic treatment applied as a final stage in E. globulus kraft pulp bleaching

Production of Microfibrillated Cellulose from Fast-Growing Poplar and Olive Tree Pruning by Physical Pretreatment

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