title: Optimization of dicarboxylic acid cellulose synthesis: reaction stoichiometry and role of hypochlorite scavengers.
abstract: The reaction conditions in terms of reaction time, sodium chlorite stoichiometry, and the effect of hypochlorite scavengers on the chlorite oxidation of dialdehyde cellulose (DAC) was studied. The impact of storage on the reactivity of DAC fibers was also investigated. It was found that chlorite oxidation of DAC is a rapid reaction, resulting in oxidation of 71% of the aldehyde after only 8 min when 2.5 times excess of sodium chlorite compared to aldehyde groups was used. Reactivity of DAC was observed to decrease quickly during the storage and only 68% of the aldehyde groups reacted after two weeks storage compared to the reaction performed with freshly prepared DAC. Hydrogen peroxide and sulfamic acid were observed to increase the reaction efficiency of chlorite oxidation by reducing the amount of side-reactions between chlorite and hypochlorite. A minor amount of sulfamic acid can be used to replace acetic acid as a catalyst.
authors.affiliation: Fibre and Particle Engineering Laboratory, University of Oulu, P.O. Box 4300, FI-90014, Finland. Electronic address: juho.sirvio@oulu.fi.
authors.forename: Juho Antti
authors.initials: JA
authors.lastname: Sirviö
authors.affiliation: Fibre and Particle Engineering Laboratory, University of Oulu, P.O. Box 4300, FI-90014, Finland. Electronic address: henrikki.liimatainen@oulu.fi.
authors.forename: Henrikki
authors.initials: H
authors.lastname: Liimatainen
authors.affiliation: Fibre and Particle Engineering Laboratory & Thule Institute, University of Oulu, P.O. Box 4300, FI-90014, Finland. Electronic address: miikka.visanko@oulu.fi.
authors.forename: Miikka
authors.initials: M
authors.lastname: Visanko
authors.affiliation: Fibre and Particle Engineering Laboratory, University of Oulu, P.O. Box 4300, FI-90014, Finland. Electronic address: jouko.niinimaki@oulu.fi.
authors.forename: Jouko
authors.initials: J
authors.lastname: Niinimäki
keywords: Cellulose; Chlorite oxidation; Dialdehyde cellulose; Dicarboxylic acid cellulose; Hypochlorite scavenger