Swelling and dissolution of cellulose, Part III: plant fibres in aqueous systems

Abstract

International audienceRaw and refined flax, hemp, abaca, sisal, jute and ramie fibres are dipped into N-methylmorpholine N-oxide (NMMO)-water with various contents of water and into hydroxide sodium (NaOH)-water. The swelling and dissolution mechanisms of these plant fibres are similar to those observed for cotton and wood fibres. Disintegration into rod-like fragments, ballooning followed or not by dissolution and homogeneous swelling are all observed as for wood and cotton fibres, depending on the quality of the solvent. Balloons are not typical of wood and cotton and they seem to be present in all plant fibres. Another interesting result is that the helical feature seen on the balloon membrane is not related to the microfibrillar angle. Plant fibres are easier to dissolve than wood and cotton. This is not related to the molar mass of the cellulose chain. Raw plant fibres keeping most its non-cellulosic components do not show the formation of balloons

Rotation and contraction of native and regenerated cellulose fibers upon swelling and dissolution: the role of morphological and stress unbalances

“…The last authors described four main dissolution modes for cotton hairs and wood fibers as a function of the quality of the solvent in N-methylmorpholine-N-oxide (NMMO)-water with various amounts of water (the lower the amount of water is, the better the solvent is): fast dissolution by fragmentation below 17% water, large swelling by ballooning, followed by complete dissolution between 18 and 24% water, large swelling by ballooning, but with no complete dissolution between 25 and 35% water, low homogeneous swelling and no dissolution above 35% water. Similar mechanisms were also observed when using other solvents like NaOH-water with or without additives (Cuissinat and Navard 2006b), ionic liquids (Cuissinat et al 2008a) and other chemicals (Cuissinat 2006) for varied plant fibers (Cuissinat and Navard 2008) and for some cellulose derivatives that were prepared under heterogeneous conditions (Cuissinat et al 2008b). In a recent paper (Le Moigne et al 2008), the existence of a centripetal radial gradient in the dissolution capacity within cotton hairs was demonstrated.…”

Dissolution mechanisms of wood cellulose fibres in NaOH–water

“…The last authors identified four main dissolution modes for wood and cotton fibres as a function of the quality of the solvent by using Nmethylmorpholine N-oxide (NMMO) with various amounts of water. The same mechanisms were also observed when using solvents as NaOH-water with or without additives (Cuissinat and Navard 2006b), ionic liquids (Cuissinat et al 2008a) and other chemicals (Cuissinat 2006) for a wide range of plant fibres (Cuissinat and Navard 2008) and some cellulose derivatives that were prepared without dissolution (Cuissinat et al 2008b). From all these studies, it was shown that the key parameter in the dissolution mechanism is the morphology of the fibre: as long as the original wall structure of the native fibre is preserved, the dissolution mechanisms are mostly similar for wood, cotton, other plant fibres and some cellulose derivatives.…”

Factors affecting the hygroexpansion of paper

“…One explanation might be that when the fibrils in the secondary wall swell transversely, the primary wall bursts at distinct spots. In these areas ''ballooning'' is visible, namely non-uniform swelling along the fibers [80].…”