Master Thesis Project: Thermal Conversion of Cellulose-Lignin Precursor Fibres into Carbon Fibres - Under tillsättning eller tillsatt, ej sökbar

Introduction
Carbon fibres have exceptionally high mechanical properties and low density and are often used as the load-bearing component in lightweight composites. Examples of fields of application are aerospace, civil engineering, and motorsports. The production of commercial carbon fibres can simplified be divided in 1) spinning of precursor fibres from polymers and 2) thermal conversion at high temperature of the precursor fibres into carbon fibres.

Today, most of the commercial carbon fibres are produced from a fossil-based polymer, polyacrylonitrile. Much research efforts are put into finding cheaper and more sustainable alternatives to the fossil-based polymer. Lignin and cellulose from the pulp mill are two promising renewable candidates, due to their high availability. The prime motivation of using lignin is its high carbon content while cellulose has a desirable molecular order.

RISE in Stockholm and Mölndal are developing biobased carbon fibres from blends of kraft lignin and cellulose. The work is currently in an interesting phase, and we therefore search for a student that want to do their Master thesis at RISE’s Lignin unit in Stockholm.

Thesis Content
This master thesis project focus on the thermal conversion steps to carbon fibres. These steps contribute to a large part of the total carbon fibre cost and are therefore very important. The primary parameters in these two steps are temperatures, residence times, stretching of the fibres, gas composition and flow etc. The choice of these process parameters will determine the gravimetric yield and tensile properties of the caron fibre. A carbon fibre with high tensile properties needs to be treated at high temperatures during conversion but will have a low yield.

RISE has a continuous experimental set-up for the conversion of spun precursor fibres into carbon fibres, in which one can control many of the process parameters. The focus in this project will be on how different temperatures and residence times in the carbonisation step influence the properties of the CF. A secondary focus is to study if the residence time in the stabilisation step can be reduced and if different atmospheres. The produced CF will be characterised by relevant techniques, e.g. tensile testing, TGA, morphology (SEM), structure (WAXS and Raman spectroscopy).

Student Profile
Master of science student majoring in chemistry, chemical engineering, material science or similar subjects. Interested and skilled in laboratory work and modification of laboratory equipment.

Starting Date
The thesis project will be performed at RISE’s Lignin unit situated close to KTH/Royal Institute of Technology, Stockholm. The thesis is expected to start in late August or September 2022.

Welcome with you application!
If this sounds interesting, you can contact Maria Sedin +46102284520 or Andreas Bengtsson +46102284648 for more information. Selection will take place on an ongoing basis and last application day 19/6 2022.

#LI-DNP