Elemental Chlorine-Free Bleaching of Soda Rapeseed Pulp
ČlánekOmezený přístuppeer-reviewedpostprintDatum publikování
2017
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Soda rapeseed pulps delignified to kappa numbers of 21.4 and 16.4 underwent elemental chlorine-free bleaching using chlorine dioxide, hydrogen peroxide, and peracetic acid as bleaching agents under laboratory conditions. Three four-stage bleaching sequences, DE(P)PPaa, D0EPD1P and D0EPD1D2, were applied to investigate the properties of bleached soda pulps, namely their brightness, zero-span breaking length and degree of polymerisation. For comparison, an oxygen-predelignified kraft softwood pulp with an initial kappa number of 10.5 was bleached under the same conditions. Soda pulps subjected to bleaching processes comprising two or three D stages were found to have a final brightness of 83.1 to 83.8% ISO, which was lower than that of 87.6 to 87.9% ISO obtained for kraft softwood pulp. The decrease in fibre strength was of only 7-9% for soda pulps, slightly greater than that of kraft softwood pulp. In contrast to fibre strength, the loss in the degree of polymerisation was considerable, roughly of 35% for soda pulps and 40 to 47% for kraft softwood pulp, depending on the bleaching sequence.
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p. 871-877
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0576-9787
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Cellulose Chemistry and Technology, volume 51, issue: 9-10
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http://www.cellulosechemtechnol.ro/pdf/CCT9-10(2017)/p.871-877.pdf
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soda rapeseed pulp, elemental chlorine-free bleaching, brightness, zero-span breaking length, degree of polymerisation, nátronová várka, řepka, ECF bělení, bělost, tržná délka s nulovým upnutím, stupeň polymerace