Ultrathin ultrastrong transparent films made from regenerated cellulose and epichlorohydrin

Mohammadhadi Moradian; Hannah Wiebe; Theo G M van de Ven

doi:10.1016/j.carbpol.2023.121131

Ultrathin ultrastrong transparent films made from regenerated cellulose and epichlorohydrin

Carbohydr Polym. 2023 Oct 15:318:121131. doi: 10.1016/j.carbpol.2023.121131. Epub 2023 Jun 20.

Authors

Mohammadhadi Moradian¹, Hannah Wiebe², Theo G M van de Ven³

Affiliations

¹ Department of Natural Resources, Cellulose Industries Group, Behbahan Khatam Alanbia University of Technology, 63973-63616 Behbahan, Iran. Electronic address: moradian@bkatu.ac.ir.
² Department of Chemistry, Quebec Centre for Advanced Materials, Pulp & Paper Research Centre, McGill University, 3420 University Street, H3A 2A7 Montreal, Quebec, Canada. Electronic address: hannah.wiebe@mail.mcgill.ca.
³ Department of Chemistry, Quebec Centre for Advanced Materials, Pulp & Paper Research Centre, McGill University, 3420 University Street, H3A 2A7 Montreal, Quebec, Canada. Electronic address: theo.vandeven@mcgill.ca.

PMID: 37479441
DOI: 10.1016/j.carbpol.2023.121131

Abstract

Thin films used in electronic devices are often petroleum-based, non-biodegradable, and non-renewable polymers. Herein, ultrathin ultrastrong regenerated cellulose films were made with a facile method by applying a solution of mildly carboxylated nanocellulose and various amounts of epichlorohydrin (ECH) as a crosslinker. The morphology and physiochemical properties of films were measured using FE-SEM, TEM, FTIR, NMR, UV-Vis, XRD, DLS, and TGA. Carboxylated cellulose with a charge content of 1.5 mmol/g was prepared to make alkaline dopes containing nanocrystalline cellulose (CNC). Then, ECH (0-50%) was added and the dope was blade cast, dried in an oven, regenerated in an acid bath, washed, and air dried to make uniform films approximately 1 μm thick. The tensile stress and elastic modulus of the films were measured and found to be 100-300 MPa and 5-12.7 GPa, respectively. Higher amounts of ECH led to stronger films. All films were over 96% transparent, insoluble in water, and absorbed 24-28% moisture. TGA analysis showed ultrathin films were thermally resistant up to 250 °C and were stable and unchanged over a month at 105 °C showing excellent thermal aging resistance. Overall, films with 5-10% ECH are extremely strong, which makes them promising bioresource-based candidates for flexible electronic applications.

Keywords: Ultrastrong film; Ultrathin film; carboxylated nanocellulose; epichlorohydrin; regenerated cellulose.