Photoyellowing of chemically modified chemithermomechanical pulps (CTMP) from Eucalyptus globulus under various atmospheres

Yasuo Kojima, Yoshiaki Kato, Yukiko Ishikura, Seung Lak Yoon, Toshihiro Ona

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Chemithermomechanical pulps (CTMP) were prepared from Eucalyptus globulus and photoirradiated, and the responses have been examined by means of ultraviolet (UV) microspectrophotometer. The absorbance in the UV spectra of fiber walls increased in the range of 300 of 350 nm as a result of photoirradiation, indicating the formation of conjugated double-bound systems in the fiber walls. These spectral changes occurred only on the irradiated surface of sheets. CTMP photoirradiation under various atmospheres indicated that the presence of oxygen in the irradiation atmosphere is not necessary for CTMP yellowing. In nitrogen or vacuum, photoyellowing was at the same level as observed under oxygen. This observation was interpreted as a result of direct elimination of proton radicals from free phenolic groups and/or cleavage of ß-aryl ether linkages. This induced probably the excited triplet state of a-carbonyl structures in CTMP, which leads to chromophore formation in the absence of oxygen. Reduction of CTMP with sodium borohydride impeded effectively the effects of photoirradiation only in the absence of oxygen. On the contrary, acetylation of CTMP had no effect in the absence of oxygen but led to photobleaching in the presence of oxygen.

Original languageEnglish
Pages (from-to)143-149
Number of pages7
JournalHolzforschung
Volume68
Issue number2
DOIs
Publication statusPublished - Feb 1 2014

Fingerprint

Pulp
Oxygen
Acetylation
Photobleaching
Fibers
Chromophores
Excited states
Ether
Free Radicals
Protons
Ethers
Nitrogen
Sodium
Irradiation
Vacuum

All Science Journal Classification (ASJC) codes

  • Biomaterials

Cite this

Photoyellowing of chemically modified chemithermomechanical pulps (CTMP) from Eucalyptus globulus under various atmospheres. / Kojima, Yasuo; Kato, Yoshiaki; Ishikura, Yukiko; Yoon, Seung Lak; Ona, Toshihiro.

In: Holzforschung, Vol. 68, No. 2, 01.02.2014, p. 143-149.

Research output: Contribution to journalArticle

Kojima, Yasuo ; Kato, Yoshiaki ; Ishikura, Yukiko ; Yoon, Seung Lak ; Ona, Toshihiro. / Photoyellowing of chemically modified chemithermomechanical pulps (CTMP) from Eucalyptus globulus under various atmospheres. In: Holzforschung. 2014 ; Vol. 68, No. 2. pp. 143-149.
@article{cf9e5629dc134c87b138ebf08f5f78a8,
title = "Photoyellowing of chemically modified chemithermomechanical pulps (CTMP) from Eucalyptus globulus under various atmospheres",
abstract = "Chemithermomechanical pulps (CTMP) were prepared from Eucalyptus globulus and photoirradiated, and the responses have been examined by means of ultraviolet (UV) microspectrophotometer. The absorbance in the UV spectra of fiber walls increased in the range of 300 of 350 nm as a result of photoirradiation, indicating the formation of conjugated double-bound systems in the fiber walls. These spectral changes occurred only on the irradiated surface of sheets. CTMP photoirradiation under various atmospheres indicated that the presence of oxygen in the irradiation atmosphere is not necessary for CTMP yellowing. In nitrogen or vacuum, photoyellowing was at the same level as observed under oxygen. This observation was interpreted as a result of direct elimination of proton radicals from free phenolic groups and/or cleavage of {\ss}-aryl ether linkages. This induced probably the excited triplet state of a-carbonyl structures in CTMP, which leads to chromophore formation in the absence of oxygen. Reduction of CTMP with sodium borohydride impeded effectively the effects of photoirradiation only in the absence of oxygen. On the contrary, acetylation of CTMP had no effect in the absence of oxygen but led to photobleaching in the presence of oxygen.",
author = "Yasuo Kojima and Yoshiaki Kato and Yukiko Ishikura and Yoon, {Seung Lak} and Toshihiro Ona",
year = "2014",
month = "2",
day = "1",
doi = "10.1515/hf-2013-0086",
language = "English",
volume = "68",
pages = "143--149",
journal = "Holzforschung",
issn = "0018-3830",
publisher = "Walter de Gruyter GmbH & Co. KG",
number = "2",

}

TY - JOUR

T1 - Photoyellowing of chemically modified chemithermomechanical pulps (CTMP) from Eucalyptus globulus under various atmospheres

AU - Kojima, Yasuo

AU - Kato, Yoshiaki

AU - Ishikura, Yukiko

AU - Yoon, Seung Lak

AU - Ona, Toshihiro

PY - 2014/2/1

Y1 - 2014/2/1

N2 - Chemithermomechanical pulps (CTMP) were prepared from Eucalyptus globulus and photoirradiated, and the responses have been examined by means of ultraviolet (UV) microspectrophotometer. The absorbance in the UV spectra of fiber walls increased in the range of 300 of 350 nm as a result of photoirradiation, indicating the formation of conjugated double-bound systems in the fiber walls. These spectral changes occurred only on the irradiated surface of sheets. CTMP photoirradiation under various atmospheres indicated that the presence of oxygen in the irradiation atmosphere is not necessary for CTMP yellowing. In nitrogen or vacuum, photoyellowing was at the same level as observed under oxygen. This observation was interpreted as a result of direct elimination of proton radicals from free phenolic groups and/or cleavage of ß-aryl ether linkages. This induced probably the excited triplet state of a-carbonyl structures in CTMP, which leads to chromophore formation in the absence of oxygen. Reduction of CTMP with sodium borohydride impeded effectively the effects of photoirradiation only in the absence of oxygen. On the contrary, acetylation of CTMP had no effect in the absence of oxygen but led to photobleaching in the presence of oxygen.

AB - Chemithermomechanical pulps (CTMP) were prepared from Eucalyptus globulus and photoirradiated, and the responses have been examined by means of ultraviolet (UV) microspectrophotometer. The absorbance in the UV spectra of fiber walls increased in the range of 300 of 350 nm as a result of photoirradiation, indicating the formation of conjugated double-bound systems in the fiber walls. These spectral changes occurred only on the irradiated surface of sheets. CTMP photoirradiation under various atmospheres indicated that the presence of oxygen in the irradiation atmosphere is not necessary for CTMP yellowing. In nitrogen or vacuum, photoyellowing was at the same level as observed under oxygen. This observation was interpreted as a result of direct elimination of proton radicals from free phenolic groups and/or cleavage of ß-aryl ether linkages. This induced probably the excited triplet state of a-carbonyl structures in CTMP, which leads to chromophore formation in the absence of oxygen. Reduction of CTMP with sodium borohydride impeded effectively the effects of photoirradiation only in the absence of oxygen. On the contrary, acetylation of CTMP had no effect in the absence of oxygen but led to photobleaching in the presence of oxygen.

UR - http://www.scopus.com/inward/record.url?scp=84900657340&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84900657340&partnerID=8YFLogxK

U2 - 10.1515/hf-2013-0086

DO - 10.1515/hf-2013-0086

M3 - Article

AN - SCOPUS:84900657340

VL - 68

SP - 143

EP - 149

JO - Holzforschung

JF - Holzforschung

SN - 0018-3830

IS - 2

ER -