Use of interleaved films to enhance the properties of all-cellulose composites

All cellulose composites (ACCs) were produced by partially dissolving alternating layers of cotton textile and cellulose film in solvent solution and heating them under an applied pressure. The ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2MIM][OAc]) combined with a co-solvent dimethyl sulfoxide (DMSO) was used in this work, and an iterative approach was employed to identify the combination of [C2MIM][OAc] and DMSO to yield the best balance of composite mechanical properties. It was revealed that the addition of the interleaved film yields a higher Young’s modulus and significantly higher interlayer peel strength compared to processing without the film. With an optimised [C2MIM][OAc] and DMSO combination, Young’s modulus was improved from 2.2 ± 0.2 GPa to 4.2 ± 0.2 GPa and peel strength reached as high as 917 ± 2 N/m. In addition, there was improved uniformity between longitudinal and transverse mechanical properties, which we attribute to an overall increase in interlayer adhesion.