Isolation of cellulose nanofibers from rapeseed straw via chlorine-free purification method and its application as reinforcing agent in carboxymethyl cellulose-based films

Narges Mirzaee; Maryam Nikzad; Rodrigo Battisti; Atefeh Araghi

doi:10.1016/j.ijbiomac.2023.126405

Isolation of cellulose nanofibers from rapeseed straw via chlorine-free purification method and its application as reinforcing agent in carboxymethyl cellulose-based films

Int J Biol Macromol. 2023 Aug 18:251:126405. doi: 10.1016/j.ijbiomac.2023.126405. Online ahead of print.

Authors

Narges Mirzaee¹, Maryam Nikzad², Rodrigo Battisti³, Atefeh Araghi⁴

Affiliations

¹ Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran.
² Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran. Electronic address: m.nikzad@nit.ac.ir.
³ Federal Institute of Education, Science and Technology of Santa Catarina, Criciúma Campus, 88813-600, Brazil.
⁴ Faculty of Veterinary Medicine, Amol University of Special Modern Technologies, Amol, Iran.

PMID: 37597636
DOI: 10.1016/j.ijbiomac.2023.126405

Abstract

In this study, cellulose nanofibers (CNFs) were successfully isolated from rapeseed straw (RS) whose valorization has been rarely investigated to date. A combined bleaching method without chlorine was applied for the purification of cellulose fibers, previously unexplored for RS. Chemical composition analysis and Fourier-transform infrared spectroscopy (FTIR) indicated that the purification method eliminated hemicellulose and reduced lignin content from 24.4 % to 1.8 %. The isolation of CNFs was performed using sulfuric acid hydrolysis under different acid concentrations (55 and 60 % v/v) and hydrolysis times (15, 30, and 45 min). The isolated CNFs were characterized by FTIR, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The formation of CNFs was confirmed by a significant increase in crystallinity index from 46.45 % of RS to >79.41 % of CNFs, depending on acid concentration and isolation duration. Carboxymethyl cellulose (CMC) films with different contents of CNFs were prepared by casting method. The mechanical properties and cytotoxicity of the prepared films were investigated. The CNFs obtained from RS via a chlorine-free purification method showed promising results for their usage as reinforcement in CMC matrix and film fabrication for various applications such as transdermal medicine and food packaging.

Keywords: Cellulose nanofibers; Chlorine-free purification; Rapeseed straw.