Comparison study of TEMPO and phthalimide-N-oxyl (PINO) radicals on oxidation efficiency toward cellulose

Gabriela Biliuta, Lidija Fras Zemljič, Mioara Drobota, Zdenka Persin, Tatjana Kreze, Karin Stana-Kleinschek, Volker Ribitsch, Valeria Harabagiu, Sergiu Coseri

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Regenerated cellulose fibers, type viscose, have been oxidized with sodium hypochlorite and catalytic amounts of sodium bromide by using two different protocols: first, involving the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) and second, employing N-hydroxyphthalimide (NHPI). The reactions were carried out at room temperature and pH = 10.5 for 2.5 h. Viscose oxidized samples were analyzed and compared in terms of the negative charged groups content, as determined by potentiometric titration and methylene blue adsorption, morphologies and crystallinities changes, as well as changes in the degree of polymerization. The highest content of the carboxylic groups and the best preservation of the morphology and molecular weight of the original material have been found in the case of using NHPI/anthraquinone as oxidation mediators. TEMPO-mediated oxidation leads to the highest depolymerization and cause significant degradation of the cellulosic material.

Original languageEnglish
Pages (from-to)502-507
Number of pages6
JournalCarbohydrate Polymers
Volume91
Issue number2
DOIs
Publication statusPublished - 16 Jan 2013
Externally publishedYes

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Keywords

  • Cellulose fibers
  • N-hydroxyphthalimide
  • Nitroxyl radicals
  • Oxidation
  • Surface modification
  • TEMPO
  • Viscose fibers

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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