Attempt to photostabilize paper made from high-yield pulp by application of UV screens in conjunction with thiols

Trichet, V.; Grelier, Stéphane; Castellan, Alain; Choudhury, Hasneen; Davidson, R. S.

doi:10.1016/1010-6030(95)04245-8

Cited by 22 publications

(11 citation statements)

References 16 publications

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“…Novel water-soluble hydroxybenzophenones containing ionic or neutral amino groups have been synthesized and proven to be efficient photostabilizers (Argyropoulos et al 2000). A favorable synergistic effect between hydroxybenzophenone or hydroxyphenylbenzotriazole type ultraviolet absorbers and thiols or sodium hypophosphite has been reported (Davidson et al 1995;Trichet et al 1996) and ascribed to the regeneration of the UV absorber by reduction (Noutary et al 1994, Gugumus 1993, whereas others have reported that the improved stability is not due to a regeneration mechanism (Cook and Ragauskas 1997). A combination of a UV screen (benzotriazole derivative), polyethylene oxide dithiol, and high charge of sucrose has also been used to photostabilize different types of high-yield pulps with some success (Petit-Conil et al 1998).…”

Section: Absorption or Scattering Of Ultraviolet Radiationmentioning

confidence: 99%

Review: Light-Induced Yellowing of Lignocellulosic Pulps – Mechanisms and Preventive Methods

Paulsson¹,

Parkås²

2012

BioResources

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This review will focus on recent progress regarding the mechanisms of light-induced discoloration of mechanical and chemimechanical pulps and on the proposed preventive treatments. It is evident that the mechanisms behind photoyellowing of lignin-rich pulps are complex and that several types of reaction pathways may coexist. Photoyellowing proceeds via one initial fast phase and a slower following phase. The fast phase has been ascribed to oxidation of free phenolic groups and/or hydroquinones and catechols to photoproducts of mainly quinonoid character. A multitude of reactions involving several lignin subunits are possible. Important intermediates are phenoxyl radicals, and to some extent ketyl radicals. The importance of the phenacyl aryl ether pathway might be more important than previously thought, even though the original content of such groups is low in lignin. Even though many preventive methods against photoyellowing have been suggested, no cost-efficient treatment is available to hinder photoreversion of lignincontaining paper permanently. Suggested methods for stabilization include chemical modification (etherification and esterification), coating the paper product, addition of radical scavengers, excited state quenchers, or ultraviolet absorbing compounds.

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Section: Absorption or Scattering Of Ultraviolet Radiationmentioning

confidence: 99%

Review: Light-Induced Yellowing of Lignocellulosic Pulps – Mechanisms and Preventive Methods

Paulsson¹,

Parkås²

2012

BioResources

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“…Traditionally, UVA based on 2-hydroxybenzophenone and hydroxyphenyl benzotriazole derivatives were thought to function by absorbing UV light and redistributing it as nonharmful thermal energy through reversible intramolecular transformations (31); however, this has recently become a matter of significant discussion. Some researchers suggest that UV absorbers may also operate as excited state quenchers of active chromophores (32)(33)(34) while others propose that these types of stabilizers act through radical scavenging or antioxidant reactions (18,35,36). According to some studies, 2-(2Ј-hydroxyphenyl) benzotriazoles may act exclusively as UV absorbers, whereas 2-hydroxybenzophenones confer additional stability through energy transfer reactions (37,38).…”

Section: The Photochemical Fate Of the Uv Stabilizersmentioning

confidence: 99%

“…Unfortunately, no individual additive has met all the commercial conditions required for successful photoyellowing inhibition (2). Combined approaches have been reported; however, they show that the use of a radical scavenger and a UVA applied jointly onto mechanical pulp can provide performance unmatched by any single additive when applied alone (17,18).…”

Section: Introductionmentioning

confidence: 99%

Photostabilizing Milled Wood Lignin with Benzotriazoles and Hindered Nitroxide†¶

Beaton¹,

Argyropoulos²

2007

Photochemistry and Photobiology

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The inhibitory processes operating when a 2(-2-hydroxyphenyl) benzotriazole-based ultraviolet absorber (UVA) and a hindered nitroxide free radical are applied to highyield pulps were studied using milled wood lignin and filter paper as a model. Using quantitative 31 P NMR it was determined that the UVA is almost completely photostable during irradiation, suggesting that its protective mechanism is based primarily on ultraviolet absorption. Furthermore, the nitroxide was found to protect the UVA from photodegradation. Analysis of irradiated lignin samples involved derivatization followed by reductive cleavage of ␤-arylether groups. The phenolic-OH groups thus released were quantified using 31 P NMR. The benzotriazole/nitroxide stabilizing system was found to cooperatively inhibit the cleavage of ␤-arylether groups. Furthermore, this system was found to have a synergistic inhibitory effect on the formation of catechol structures. These results suggest that the synergism observed between benzotriazole-based UV screens and nitroxyl radicals on the inhibition of yellowing could be a result of their ability to slow the formation of catechol structures and ␤-O-4 cleavage in addition to the possibility of a UVA-regeneration mechanism.

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“…Among these are different classes of radical scavengers, UV absorbers, and fluorescent whitening agents (Nourary et al 1994;Cole et al 1996;Guo and Gray 1996;Trichet et al 1996;Ragauskas and Cook 1997;Li et al 1999;McGarry et al 1999). Sulfur-containing compounds, such as thioalcohols, mercapto esters and sulfinates, have also been studied (Cole et al 2000;Bourgoing and Robert 2001).…”

Section: Introductionmentioning

confidence: 96%

Brightness stabilisation of bleached high-yield pulps by novel sulfur-containing inhibitors

2006

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The stabilisation of a peroxide-bleached chemothermomechanical pulp against light-induced yellowing by novel sulfur-containing radical-scavenging compounds was investigated. Substances were identified that lack the unpleasant odour typical for compounds containing thiol groups. High inhibition effects were observed when the sulfur compounds were combined with small amounts of hindered amines and UV absorbers. A novel group of thiols isolated from biomatter was among the sulfur-containing inhibitors. Photoyellowing could be avoided for 3 years in real conditions when the inhibitors were applied as part of a coating. The ability of the thiol compounds to scavenge phenoxy radicals was demonstrated by ESR spectroscopy of irradiated chemithermomechanical pulp sheets. The results are encouraging for efficient brightness stabilisation of high-yield pulps.

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Attempt to photostabilize paper made from high-yield pulp by application of UV screens in conjunction with thiols

Cited by 22 publications

References 16 publications

Review: Light-Induced Yellowing of Lignocellulosic Pulps – Mechanisms and Preventive Methods

Review: Light-Induced Yellowing of Lignocellulosic Pulps – Mechanisms and Preventive Methods

Photostabilizing Milled Wood Lignin with Benzotriazoles and Hindered Nitroxide†¶

Brightness stabilisation of bleached high-yield pulps by novel sulfur-containing inhibitors

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