Cellulose Regeneration and Chemical Recycling: Closing the “Cellulose Gap” Using Environmentally Benign Solvents

• Published in: Macromolecular materials and engineering Vol. 305; no. 4
• Main Authors: El Seoud, Omar A., Kostag, Marc, Jedvert, Kerstin, Malek, Naved I.
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.04.2020
• Subjects: Additives; Blending; Cellulose; cellulose blends; Cellulose fiber; Cellulose fibers; Cellulose films; cellulose nanoparticles; cellulose regeneration; chemical recycling; Depolymerization; Dissolution; Dissolving; Ethylene; Ionic liquids; Membranes; Mixing; Nanoparticles; Natural fibers; Non-wovens; nonwovens; Polyethylene terephthalate; Recycling; Regeneration; Solvents; Textile blends; Textile fibers; Wood
• ISSN: 1438-7492; 1439-2054; 1439-2054
• DOI: 10.1002/mame.201900832

Strategies to mitigate the expected “cellulose gap” include increased use of wood cellulose, fabric reuse, and recycling. Ionic liquids (ILs) are employed for cellulose physical dissolution and shaping in different forms. This review focuses on the regeneration of dissolved cellulose as nanoparticles, membranes, nonwoven materials, and fibers. The solvents employed in these applications include ILs and alkali solutions without and with additives. Cellulose fibers obtained via the carbonate and carbamate processes are included. Chemical recycling (CR) of polycotton (cellulose plus poly(ethylene terephthalate)) is addressed because depending on the recycling approach employed, this process is akin to regeneration. The strategies investigated in CR include preferential dissolution or depolymerization of one component of the blend, and separation of both components using ILs. It is hoped that this review focuses the attention on the potential applications of regenerated cellulose from its solutions and contributes to the important environmental issue of recycling of used materials. Ionic liquids and alkaline solutions dissolve cellulose physically. The resulting solutions are used to fabricate good‐quality fibers, nanoparticles, membranes, and nonwoven materials with interesting properties and relevant applications. Strategies for chemical recycling of polycotton (cellulose poly(ethylene terephthalate) blends) are discussed. Processes based on using these solvents have much less environmental impact than some of the existing ones.