Accessible Unlicensed Requires Authentication Published by De Gruyter August 6, 2011

Oxidative stabilisation of kraft lignin for carbon fibre production

Ida Brodin, Marie Ernstsson, Göran Gellerstedt and Elisabeth Sjöholm
From the journal

Abstract

With the aim of investigating kraft lignin as a raw material for carbon fibre production, different lignins have been stabilised in air at conditions varied according to a full factorial experimental design. The lignins under examination were purified kraft lignin powders originating from birch, spruce/pine and Eucalyptus globules, as well as lignin fibres originating from birch with 5% poly(ethylene oxide) (PEO) added as a plasticiser. The influence of temperature, time and heating rate on yield and glass-transition temperature (Tg) was investigated. The highest yield was achieved after stabilisation at 280°C during 2 h with a heating rate of 0.2°C min-1. The Tg of all lignin powders was increased when stabilisation occurred under harsher conditions. X-ray photoelectron spectroscopy analysis (XPS) of both the outer surface and the cleaved cross-section of individual lignin/PEO fibres showed a clear gradient in the degree of chemical modification, with the major change occurring on the surface resulting in the appearance of a skin-core structure after stabilisation. The behaviour of the lignin fibres during stabilisation is similar to that of pitch-based fibres, indicating good possibilities for lignin as raw material for carbon fibre production.


Corresponding author. Innventia AB, Box 5604, SE-114 86, Stockholm, Sweden Fax: +46 8 411 55 18

Received: 2011-3-3
Accepted: 2011-7-8
Published Online: 2011-08-6
Published in Print: 2012-02-01

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