CPMAS 13C NMR Analysis of Fully Bleached Eucalypt Pulp Samples: Links to Handsheet Hygroexpansivity and Strength Properties

Pulkkinen, Iiro; Fiskari, Juha; Alopaeus, Ville

doi:10.3923/jas.2009.3991.3998

Cited by 8 publications

(10 citation statements)

References 20 publications

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“…In the present work, a value of 0.0097% was obtained for this parameter. This calculated value is far lower than the measured values ranging from around 0.02% to 0.21%, as quoted for the hygro-expansion of paper handsheets (Lee, Pawlak, & Heitmann, 2012;Pulkkinen, Fiskari, & Alopaeus, 2009a). For such products the high value does not seem to be connected to the amorphous cellulosic component of the product, but rather to the swelling propensity of the hemicelluloses, that are present in the specimens.…”

Section: Bulk Propertiescontrasting

confidence: 73%

“…For such products the high value does not seem to be connected to the amorphous cellulosic component of the product, but rather to the swelling propensity of the hemicelluloses, that are present in the specimens. Additionally, the specific ultrastructural organization of the cellulose microfibrils within the fiber cell walls, which is not present in our model of amorphous cellulose, is also given as another reason for a high hygro-expansion figure of paper products (Pulkkinen et al, 2009a(Pulkkinen et al, , 2009b.…”

Section: Bulk Propertiesmentioning

confidence: 94%

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The hygroscopic power of amorphous cellulose: A modeling study

Mazeau

2015

Carbohydrate Polymers

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Section: Bulk Propertiescontrasting

confidence: 73%

Section: Bulk Propertiesmentioning

confidence: 94%

The hygroscopic power of amorphous cellulose: A modeling study

Mazeau

2015

Carbohydrate Polymers

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“…However, microfibrillated and whiskered cellulose showed the same sorption isotherm even though they had different crystallinities and morphologies [53]. Contrary to expectations, no clear correlation between the crystallinity index and the hygroexpansion of paper could be found [69]. This might be related to the adverse effects that are reported for cellulose such as expansion during drying and shrinkage during water absorption [75][76][77].…”

Section: Hygroexpansion Of Cellulosecontrasting

confidence: 49%

“…Ways of influencing the moisture content and moisture sorption kinetics are reviewed below. Different chemical treatments that influence the sorption isotherms of the fibers have been reported [69,112,118,119,120]. The treatment of flax fibers with acetic anhydride and styrene reduced the water uptake, whereas silane and maleic anhydride do not have such a positive effect [118].…”

Section: Water Sorption Of Single Fibersmentioning

confidence: 99%

“…The exact relative amount of crystalline and amorphous cellulose depends on the species [69]. Compared to lignin and hemicellulose, cellulose is a rather crystalline material and therefore its swelling capability-determined by the amorphous regions-is low and sometimes neglected when talking about fiber hygroexpansion [46,70,71] or homogenized with the swelling capability of hemicelluloses [47].…”

Section: Hygroexpansion Of Cellulosementioning

confidence: 99%

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Factors affecting the hygroexpansion of paper

Lindner

2017

J Mater Sci

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Paper is a widely used packaging material and is nowadays regaining importance, e.g., as bio-based and biodegradable material. Moreover, new technologies such as polymer-fiber composites, printed electronics and the deep drawing of paper are developing. The process stability and also the resulting quality of paper converting processes such as coating, metallization, printing, and the printing of electronics are highly affected by the hygroexpansion of paper. In order to reduce production instability and to choose and develop paper substrates with ideal characteristics, critical parameters need to be known. This paper offers an extensive overview of those parameters, starting at a molecular and microscopic level with the effect of the constituents and morphology of single fibers, before moving on to paper contents, chemical modifications and additives and finally concluding with paper production and fiber network modification. It was found that the major influences are single fiber sorption, inter-fiber contacts, microfibril angle, fiber morphology (length, width, curliness) and fiber orientation. This review gives new ideas and insights for technologists working in research, development and production optimization of paper-based products.

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Synergism of enzymes in chemical pulp bleaching from an industrial point of view: A critical review

Immerzeel

Fiskari

2022

Can J Chem Eng

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Enzymes are biological catalysts and are very specific, catalyzing either a single chemical reaction or a limited number of closely related reactions. For example, xylanases are enzymes that catalyze the cleavage of polymeric xylan and thereby break down this hemicellulose. The first xylanase enzyme preparations used in the bleaching process of chemical pulp also contained cellulase, which catalyzes the hydrolysis of cellulose. This obviously had an adverse effect on pulp yield and quality. Unfortunately, this setback gave enzyme-assisted pulp bleaching a negative reputation. At a later stage, enzyme producers managed to engineer enzyme production strains that generated cellulase-free xylanase preparations. However, due to the initial negative experiences with the earlier enzyme mixtures, only a limited number of companies in the pulp industry have seriously considered using these so-called second-generation enzymes in their bleach plants. It is apparent that these improved enzyme preparations would bring about significant benefits in terms of chemical cost savings and effluent quality. In addition to xylanaseaided bleaching, it is possible to improve the effectivity further by adding other enzymes, such as lipase and esterase, to create an enzyme cocktail. This may be particularly beneficial in the bleaching of hardwood pulp, such as white birch, which often encounters complex and troublesome problems with wood extractives. By adding different types of enzymes at more than one position in the fiberline, even further improvements are possible. The main objective of this review is to discuss the advantages of incorporating modern enzyme preparations in the bleaching of chemical pulp.

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CPMAS 13C NMR Analysis of Fully Bleached Eucalypt Pulp Samples: Links to Handsheet Hygroexpansivity and Strength Properties

Cited by 8 publications

References 20 publications

The hygroscopic power of amorphous cellulose: A modeling study

The hygroscopic power of amorphous cellulose: A modeling study

Factors affecting the hygroexpansion of paper

Synergism of enzymes in chemical pulp bleaching from an industrial point of view: A critical review

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