Preparation of carbon fibre preform from acetylated cellulose and nano-crystalline cellulose

Harahap, Mahyuni (2018). Preparation of carbon fibre preform from acetylated cellulose and nano-crystalline cellulose. University of Birmingham. M.Sc.

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Abstract

The search for precursors that are bio-based, renewable and biodegradable has attracted significant. Recently, nano-crystalline cellulose (NCC) has been considered as a potential precursor for the production of carbon fibre. However, its crystallinity and strong hydrogen bonding in the NCC structure prevents it from being dissolved in common solvents. The main aims of this study were: (i) to acetylate NCC; (ii) to electro-spin NCC suspension using polyacrylonitrile (PAN) as the “carrier” polymer; (iii) to extrude NCC and acetylated NCC via wet-spinning; and (iv) to pyrolyse the wet-spun NCC fibres. In this study, the rod-like particles of NCC with diameters in the range 2.0 - 4.8 nm and lengths of 46 - 114 nm were characterised using a transmission electron microscope. The surface acetylation of NCC was achieved and the degree of substitution was determined using \(^1\)\(^3\)C solid-state nuclear magnetic resonance spectroscopy. The crystallinity of the NCC before and after acetylation were 78% and 68% respectively.

The introduction of PAN, dissolved in DMSO, into NCC increased the conductivity of the solution from 15.41 to 21.59 µS/cm. This solution was electro-spun to obtain fibres diameters in the range 500 to 200 nm. Wet-spun NCC fibres from unacetylated and acetylated NCC was pyrolysed at 900 ºC in an inert atmosphere. The morphologies and the cross-section areas of the spun-fibres before and after pyrolysis were found to be void-free. Raman spectroscopy was used to obtain the ID/IG ratio of carbonised fibres; this was 0.83 - 0.84.

Type of Work:

Thesis (Masters by Research > M.Sc.)

Award Type:

Masters by Research > M.Sc.

Supervisor(s):