Controlled molecular reorientation enables strong cellulose fibers regenerated from ionic liquid solutions

Johan Sundberg; V. Guccini; Karl Håkansson; G. Salazar-Alvarez; Guillermo Toriz Gonzalez; Paul Gatenholm

doi:10.1016/j.polymer.2015.08.035

Controlled molecular reorientation enables strong cellulose fibers regenerated from ionic liquid solutions
Journal article, 2015

Cellulose is difficult to solubilize and undergoes thermal decomposition prior to melting. In recent years ionic liquids have been evaluated as solvents of cellulose. In the regeneration process the non-solvent governs the resulting material's crystallinity. Water adsorbs to amorphous cellulose, acts as plasticizer and lowers the T g , hence the degree of crystallinity will affect the potential strain induced reorientation. We prepared regenerated cellulose fibers form ionic liquid using different non-solvents. The influence of shear forces upon cellulose chain alignment during extrusion was simulated in silica based upon rheological measurements. The regenerated fibers had different physical, morphological and mechanical properties. Molecular re-orientation in fibers induced by mechanical strain, at humidities above the T g , resulted in much improved mechanical properties with the Young's modulus reaching 23.4 ± 0.8 GPa and the stress at break 504.6 ± 51.9 MPa, which is comparable to commercially available cellulose fibers.

Stresses

Rheological measurements

Solvents

Pyrolysis

Regenerated cellulose fibers

Strain

Solutions

Degree of crystallinity

Liquids

Ionic liquid

Decomposition

Textile fibers

Resulting materials

Mechanical properties

Cellulose Fibers

Amorphous cellulose

Cellulose

Regenerated cellulose

Regeneration process

Melting

Elastic moduli

Molecular reorientation

Ions

Molecular orientation

Fibers

Natural fibers

Reorientation

Ionic liquids