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

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

研究成果: ジャーナルへの寄稿学術誌査読

4 被引用数 (Scopus)

抄録

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.

本文言語英語
ページ(範囲)143-149
ページ数7
ジャーナルHolzforschung
68
2
DOI
出版ステータス出版済み - 2月 1 2014

!!!All Science Journal Classification (ASJC) codes

  • 生体材料

フィンガープリント

「Photoyellowing of chemically modified chemithermomechanical pulps (CTMP) from Eucalyptus globulus under various atmospheres」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル