G4 Doctoral dissertation (monograph)
Oxidative Reactions of Cellulose under Alkaline Conditions (2020)

Adibi Larijani, A. H. (2020). Oxidative Reactions of Cellulose under Alkaline Conditions [Doctoral dissertation]. Jyväskylän yliopisto. JYU Dissertations, 217. http://urn.fi/URN:ISBN:978-951-39-8157-0

JYU authors or editors

Publication details

All authors or editors: Adibi Larijani, Amir Houshang

eISBN: 978-951-39-8157-0

Journal or series: JYU Dissertations

eISSN: 2489-9003

Publication year: 2020

Number in series: 217

Publisher: Jyväskylän yliopisto

Place of Publication: Jyväskylä

Publication country: Finland

Publication language: English

Persistent website address: http://urn.fi/URN:ISBN:978-951-39-8157-0

Publication open access: Openly available

Publication channel open access: Open Access channel

Abstract

The purpose of this investigation was to elucidate the influence of oxygen, gas pressure, and temperature on the oxidative degradation of cellulose and the formation of degradation products under alkaline conditions. In order to simplify the reaction system the experiments were carried out with the cellulose model compound cellobiose. Reaction products were determined and identified by GCFID and GC-MSD as their per(trimethylsilyl)ated derivatives. About 37 degradation products were qualitatively identified of which 33 degradation products were quantitatively evaluated. The degradation products were divided into oxidative and non-oxidative degradation products. The main degradation products were glucose as well as glycolic, lactic, glyceric, 3,4-dihydroxybutanoic, 3-deoxypentonic, and glucoisosaccharinic acids. An inhibiting character of oxygen upon cellobiose degradation was observed. At lower temperatures an increase in oxygen pressure caused the formation of non-oxidative degradation products in trace amounts. The formation of oxidative degradation products was kinetically and of non-oxidatives thermodynamically favored. The kinetic calculations revealed that at room temperature the degradation of cellobiose proceeded four times slower in air than in 1 bar nitrogen. Furthermore, the activation energy for cellobiose degradation in 1 bar nitrogen was 79 kJ/mol and rose to 122 kJ/mol in air. Based on the obtained results and made observations a new ionic reaction mechanism was postulated.

Keywords: cellulose; gas chromatography; mass spectrometry; reaction mechanisms

Free keywords: cellobiose; alkaline oxidative degradation; degradation products; kinetics; activation energy

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2020