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Titolo:
Heat- and light-induced brightness reversion of bleached chemical pulps
Autore:
Chirat, C; De la Chapelle, V;
Indirizzi:
Ctr Tech Papier, F-38044 Grenoble 9, France Ctr Tech Papier Grenoble France 9 ech Papier, F-38044 Grenoble 9, France Ecole Francaise Papeterie & Ind Graph, F-38402 St Martin Dheres, France Ecole Francaise Papeterie & Ind Graph St Martin Dheres France F-38402 ce
Titolo Testata:
JOURNAL OF PULP AND PAPER SCIENCE
fascicolo: 6, volume: 25, anno: 1999,
pagine: 201 - 205
SICI:
0826-6220(199906)25:6<201:HALBRO>2.0.ZU;2-Q
Fonte:
ISI
Lingua:
ENG
Keywords:
bleached pulps; chlorine free bleaching; kraft pulps; bisulfite pulps; hardwoods; softwoods; color reversion; brightness; aging; heat; light; ketones; aldehydes; carboxyl groups;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Engineering, Computing & Technology
Citazioni:
14
Recensione:
Indirizzi per estratti:
Indirizzo: Chirat, C Ctr Tech Papier, BP 251, F-38044 Grenoble 9, France Ctr Tech Papier BP 251 Grenoble France 9 044 Grenoble 9, France
Citazione:
C. Chirat e V. De la Chapelle, "Heat- and light-induced brightness reversion of bleached chemical pulps", J PULP PAP, 25(6), 1999, pp. 201-205

Abstract

Elemental chlorine free (ECF) and totally chlorine free (TCF) bleached pulps of different types (kraft, bisulphite, softwood and hardwood) were analyzed and submitted to heat and light aging. TCF pulps had residual kappa numbers between 2 and 4, and higher carboxyl content than the corresponding ECF pulps. TCF pulps were generally less stable to heat than ECF pulps. The effect on light exposure was less obvious even though significant differences could be observed among pulps. Some oxidized groups were created selectively on cellulose and their effect on heat and light exposure was studied. Ketone groups impaired brightness reversion upon heat significantly: whereasaldehyde groups at C-2-C-3 had only a minor effect. Carboxyl groups at C-2-C-3 were shown to affect brightness stability to heat. Brightness stability upon light exposure, however was affected neither by ketones and aldehydes, nor by carboxyl groups. Finally it was shown that for a given brightnessloss, cellulose was less degraded when exposed to light than to heat, suggesting different mechanisms.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 14:46:46