Recycling of waste cotton fabrics into regenerated cellulose films through three solvent systems: A comparison study

Abstract

Large amounts of textile waste are generated every year and disposed of through landfill or incineration, leading to numerous environmental and social issues. In this work, the dissolution of three typical waste cotton fabrics (t‐shirts, bed sheets and jeans) in NaOH/urea aqueous solution, H2SO4 aqueous solution, and LiCl/DMAc solution was investigated. Compared to different types of cotton fabrics, the effects of three solvents on the dissolution of fabrics were more obvious, leading to the significant changes in the structure and properties of regenerated cellulose films. Cotton fabrics (about 2%–5%) were rapidly dissolved (8 min) in H2SO4 and NaOH/urea solvents after acid pretreatment, while the dissolution in LiCl/DMAc solvent did not need any pretreatment, but a lower cellulose concentration (1%), higher dissolution temperature (80°C), and longer dissolution time (24 h) were required. The films produced from bed sheets in NaOH/urea solution exhibited the highest tensile strength, thermal stability, and water vapor barrier property. It was because of the stronger cellulose chain entanglement and hydrogen bonds induced by the higher cellulose concentration in NaOH/urea solution. Therefore, this work proves the feasibility to recycle waste cotton fabrics into biodegradable cellulose films, which can be potentially used in various food and agricultural applications.

Research and Technology in Graphic Engineering and Design at the Universitat Politècnica de Catalunya

“…Actualment s'està explorant l'ús de líquids iònics per dissoldre la cel•lulosa que trobem en les peces de roba rebutjades i obtenir altres productes, com per exemple films biodegradables que es poden aplicar en el sector de l'embalatge (Zhou & Wang, 2021). Una dificultat habitual en el reciclatge, és que una part important dels productes tèxtils estan formats per mescles heterogènies de fibres, per exemple cotó i polièster.…”

Recent progress in cellulose-based electrospun nanofibers as multifunctional materials

“…The most effective way is to directly convert cellulose into nanofibers; however, raw materials have to be dissolved or melted for electrospinning. Although several cellulose solvent systems have been developed, such as ionic liquids, 36 N -methylmorpholine- N -oxide (NMMO), 37 LiCl/DMAc, 38 tetra( n -butyl)ammonium hydroxide/dimethyl sulfoxide (TBAH/DMSO), 39 alkali/urea aqueous solution, 40 and sulphuric acid solution, 41 most of them are not suitable for electrospinning due to their high boiling point or high salt concentration. LiCl/DMAc has been proved as an effective solvent, and recent research focused on improving the current process and looking for new solvent systems.…”

Construction of chevaux-de-frise from cellulose nanocrystals to enable mechano-bactericidal activity on recycled waste cotton films

“…16 In our previous work, cellulose nanocrystals (CNCs) and regenerated cellulose (RC) films were successfully prepared from waste cotton fabrics. 17,18 Especially, the obtained CNCs are rigid and possess a rod/needle-like shape (diameter of 5–10 nm and length of about 100 nm). 17 This morphology is similar to the engineered nanopillars, but the mechano-bactericidal activity of CNCs has never been reported.…”