Thermal, chemical and morphological properties of carbon fibres derived from chemically pre-treated wool fibres

In this work, the feasibility of using wool fibre as a carbon fibre precursor was explored as well as whether chemical treatments to wool fibre can increase the carbon fibre yield and properties of the produced carbon fibres. Wool fibres were treated with a range of chemicals including lignin, tannic acid, polystyrene sulphonate, and chlorine in conjunction with a polyamide resin. The treated fibres were stabilised in air at 160 °C followed by pyrolysis at 800 °C under a nitrogen atmosphere. The resulting carbon fibres were characterised in terms of carbon yield, tensile strength, surface roughness, porosity, crystal structure and surface hydrophobicity. The carbon fibre yield was 16.7% for the untreated while the lignin pre-treatment increased the carbon yield up to 25.8%. Generally the surface of the carbon fibre made from both untreated and treated fibre exhibited high hydrophilicity except the lignin and chlorine/polyamide resin-treated fibre which showed hydrophobicity. Although the tensile strength achieved for the various produced carbon fibre was poor compared to a commercially available pitch-based carbon fibre, the developed carbon fibre still can be utilised in thermoplastic composite manufacturing.