Cellulose processing in ionic liquid based solvents
Doktorsavhandling, 2014

As the most abundant polymer in nature, cellulose has an undisputed role among the raw materials to be used in a sustainable future. From its native form, in wood or straw, cellulose can be processed into products such as paper and board. Through dissolution and precipitation, the range of cellulose based products can be increased to include textile fibers, thin continuous films, foams and membranes. Since cellulose is insoluble in most conventional solvents, ongoing research worldwide aims to find new, efficient and environmentally friendly solvent systems for biomass in general, and for cellulose in particular. In this thesis, the solvent of focus was 1-ethyl-3-methylimidazolium acetate, commonly abbreviated as EMIMAc. It is an ionic liquid, and belongs to a class of solvents which was basically unexploited by cellulose chemists until just over a decade ago. Results show that cellulose that is dissolved in EMIMAc, with or without a cosolvent, can be spun into continuous textile fibers using airgap spinning or wet spinning, or be cast into films. The properties of the produced fiber vary depending on the solution, cellulose sources and spinning parameters, such as drawing. For example, the regeneration medium was found to be of great importance for the crystallinity of regenerated films. Properties of regenerated cellulose can be further altered by drying conditions. It was also shown that some residual coagulation medium (water), which is time-consuming to remove in a solvent recycling step, can be tolerated in the EMIMAc to some extent if cellulose concentration or degree of polymerization is low. Finally, esterification of cellulose in EMIMAc was found to be improved by using cosolvents to regulate unintended acetylation, which until now, has been the dominant result in such reactions.

esterification

cellulose

NMR spectroscopy

solution spinning

dissolution

ionic liquids

cellulose derivatives

rheology

crystallinity

KA-salen, Kemigården 4, Chalmers tekniska högskola
Opponent: Prof. Herbert Sixta, Aalto University, Finland

Författare

Carina Olsson

Chalmers, Kemi- och bioteknik

Effect of methylimidazole on cellulose/ionic liquid solutions and regenerated material therefrom

Journal of Materials Science,; Vol. 49(2014)p. 3423-3433

Artikel i vetenskaplig tidskrift

Modification of crystallinity and pore size distribution in coagulated cellulose films

Cellulose,; Vol. 20(2013)p. 1657-1667

Artikel i vetenskaplig tidskrift

Wet Spinning of Cellulose from Ionic Liquid Solutions–Viscometry and Mechanical Performance

Journal of Applied Polymer Science,; Vol. 127(2013)p. 4542-4548

Artikel i vetenskaplig tidskrift

Influence of water on swelling and dissolution of cellulose in 1-ethyl-3-methylimidazolium acetate

Carbohydrate Polymers,; Vol. 99(2014)p. 438-446

Artikel i vetenskaplig tidskrift

Direct Dissolution of Cellulose: Background, Means and Applications

Cellulose - Fundamental Aspects,; (2013)p. 143-178

Kapitel i bok

Ämneskategorier

Polymerkemi

Pappers-, massa- och fiberteknik

Textil-, gummi- och polymermaterial

Materialkemi

Styrkeområden

Materialvetenskap

ISBN

978-91-7385-999-8

KA-salen, Kemigården 4, Chalmers tekniska högskola

Opponent: Prof. Herbert Sixta, Aalto University, Finland