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Cellulose
Published in Antonio Paesano, Handbook of Sustainable Polymers for Additive Manufacturing, 2022
At elevated temperatures cellulose does not melt but decomposes, hence to obtain liquid cellulose and combine it with other ingredients, cellulose has to be dissolved or chemically modified. However, cellulose is insoluble and only partly soluble in water and most common solvents due to the preferential formation of intra- and intermolecular hydrogen bonds (Olsson and Westman 2013), and to date only a few solvent systems can dissolve cellulose. Current aqueous and non-aqueous cellulose solvents suffer from insufficient solvation power and high toxicity (Olsson and Westman 2013). Hereafter two dissolution processes successfully employed for cellulose for AM are mentioned: one based on N-methylmorpholine-N-oxide (NMMO) (Olsson and Westman 2013), the other on ionic liquids (ILs), a family of liquids that consist entirely of ions and have a Tg or Tm below 100°C (Mäki-Arvela et al. 2010; Hauru et al. 2012; Gunasekera et al. 2016). The NMMO process offers the benefit of having been successfully implemented on industrial scale, while ILs easily dissolve cellulose and are less hazardous than other solvents.
Fibre reinforcements
Published in A.R. Bunsell, S. Joannès, A. Thionnet, Fundamentals of Fibre Reinforced Composite Materials, 2021
R. Bunsell, S. Joannes, A. Thionnet
Throughout most of history there were only natural fibres available however during the eighteenth and nineteenth centuries chemists in a number of European countries examined ways of dissolving cellulose. The goal of this research was to produce artificial silk for the textile industry. The first commercialised man-made fibres were produced by the Comte H. de Chardonnet in France in 1892 however these cellulose nitrate fibres were highly inflammable. Two years later Charles Frederick Cross together with Edward John Bevan and Clayton Beadle, in England, patented viscose silk in 1894 which dissolved the cellulose in sodium hydroxide after first reacting it with carbon disulphide. This gave a viscous solution from which the name “viscose cellulose” or simply “viscose” was derived. The cellulose was regenerated in dilute sulfuric acid and was to find wide use. In 1905, Courtaulds in the UK began the first commercial production of these viscose fibres. Viscose rayon found a ready market in the textile industry but also it became an important reinforcement for rubber as in tyres, pulley belting and other such applications. Development of rayon fibres was stimulated in the twentieth century by the appearance of synthetic Nylon at the end of the 1930s, then followed by polyester, and high tenacity rayon was developed in the 1940s. A technique known as the Lyocell route was developed in the 1980s by dissolving cellulose in N-methylmorpholine N-oxide (NMMO) and together with the viscose process these have become the main means of production.
Cellulose-Based NanoBioMaterials
Published in Bhupinder Singh, Om Prakash Katare, Eliana B. Souto, NanoAgroceuticals & NanoPhytoChemicals, 2018
Michael Ioelovich, Sumant Saini, Teenu Sharma, Bhupinder Singh
Along with nanoparticles and nanofibrils, nanofilaments with a diameter of 100–1000 nm may also be prepared using an electrospinning technique (Shin et al., 2001; Quan et al., 2010; Vargas, 2010; Zhao et al., 2011). Various cellulose solvents have been used for preparation of nanofilaments, such as lithium chloride (LiCl)/dimethylacetamide (DMAc), N-methylmorpholine-N-oxide (NMMO), and ionic liquids (Kulpinski, 2005; Kim et al., 2006; Frey, 2008; Quan et al., 2010). Structural studies show that cellulose nanofilaments, prepared from solutions in LiCl/DMAc, were amorphous, while the nanofilaments obtained from solutions in NMMO were semicrystalline. The electrospun nanofilaments can also be produced from chitosan, carboxymethyl cellulose, and other derivatives of cellulose. For instance, solutions of chitosan in dilute acetic or trifluoroacetic acid were used for electrospinning to obtain nanofilaments with a diameter ranging between 60 and 100 nm (Ohkawa et al., 2004; Schiffman and Schauer, 2007; Zhao et al., 2011).
Upcycling textile wastes: challenges and innovations
Published in Textile Progress, 2021
Zunjarrao Kamble, Bijoya Kumar Behera
When the polymer or oligomer is recovered from fibres for reuse, it is termed polymer or oligomer recycling and there are various ways to recover polymer or oligomer from waste textiles. Waste cotton textiles for example can be used to produce regenerated cellulose fibres and one well-known method is to dissolve cotton-based waste textiles using N-methylmorpholine N-oxide (NMMO) solution to produce cellulose pulp (Haule, Carr, & Rigout, 2016). This pulp can be processed in similar manner to that of viscose rayon yarn production process to produce yarn. Another method is selective dissolution in case of polyester/cotton blended textiles using the ionic liquid (1,5-diazabicyclo[4.3.0]non-5-enium acetate) (Haslinger, Hummel, Anghelescu-Hakala, Määttänen, & Sixta, 2019). The cellulose is dissolved using ionic liquid and processed to produce multifilament yarn. However, this method has not been a commercial success. An enzymatic hydrolysis is another approach to recover valuable monomer from waste textiles (Li, Hu, Du, & Lin, 2019). Enzymes such as cellulase and β- glucosidase have been reported to enable the recovery of glucose from waste textiles.