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Titolo:
The darkening reactions of TMP and BTMP during alkaline peroxide bleaching
Autore:
Leary, G; Giampaolo, D;
Indirizzi:
Alberta Res Council, Edmonton, AB T6H 5X2, Canada Alberta Res Council Edmonton AB Canada T6H 5X2 monton, AB T6H 5X2, Canada PAPRICAN, Pointe Claire, PQ H9R 3J9, Canada PAPRICAN Pointe Claire PQ Canada H9R 3J9 ointe Claire, PQ H9R 3J9, Canada
Titolo Testata:
JOURNAL OF PULP AND PAPER SCIENCE
fascicolo: 4, volume: 25, anno: 1999,
pagine: 141 - 147
SICI:
0826-6220(199904)25:4<141:TDROTA>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
HYDROGEN-PEROXIDE; MECHANICAL PULPS; LIGNIN; OXIDATION; OXYGEN; ETHER; MEDIA; COLOR;
Keywords:
thermomechanical pulps; bleached pulps; peroxide bleaching; alkali; bibliographies; brightening; brightness; chemistry;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Engineering, Computing & Technology
Citazioni:
25
Recensione:
Indirizzi per estratti:
Indirizzo: Leary, G Alberta Res Council, POB 8330, Edmonton, AB T6H 5X2, Canada Alberta Res Council POB 8330 Edmonton AB Canada T6H 5X2 2, Canada
Citazione:
G. Leary e D. Giampaolo, "The darkening reactions of TMP and BTMP during alkaline peroxide bleaching", J PULP PAP, 25(4), 1999, pp. 141-147

Abstract

Alkali darkening is associated with carbonyl groups in the pulps. It can be prevented by pretreatment with sodium borohydride. It is partially reversed by peroxide treatment. Chemical treatments and UV spectroscopy indicate that alkali darkening of unbleached TMP forms quinones and some aryl ketones or aldehydes. Darkening of BTMP appears to result in the formation of stilbenes, aryl ketones or aldehydes and small amounts of coniferaldehydes. Darkening of BTMP is more severe at high pHs, high manganese concentration and high temperature. At 120 degrees C the presence of residual peroxide doesnot fully inhibit alkali darkening.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/11/20 alle ore 18:18:39