Control of the aqueous solubility of cellulose by hydroxyl group substitution and its effect on processing

Native cellulose is insoluble in water, despite the high number of hydrogen bonding sites per chain, as molecules preferably bond to each other, preventing its use industrial applications. The modification has received considerable recent attention, motivated by move away from conventional petroleum-based, water-soluble polymers, however, a systematic analysis effects rare. Herein detailed study hydroxypropyl (HP)- and (2-hydroxypropyl) trimethylammonium chloride-modified cellulose, with degrees substitution (DS) determined NMR, establishes modification-property relationships. TEM, small-angle X-ray scattering rheology demonstrated that increasing DS gradually changes aqueous solubility, resulting formation different morphologies, including micron-sized aggregates, needle-like nanoparticles (CNPs) solvated molecules. It was found dispersions HP 50%, assigned ‘sweet spot’ modification, are suitable for fiber formation. shown this state material can be easily detected rheo-optical methods based on birefringence. Using structural analysis, molecular dynamics simulation fiber-spinning results, it proposed co-existing CNPs molecules, interacting via H-bonding, form network which orients under shear, acting precursor solutions.