Development and characterization of biodegradable films based on carboxymethylcellulose with incorporated eucalyptus (Eucalyptus grandis) nanocellulose

Biodegradable and/or renewable-source polymers, such as carboxymethylcellulose (CMC), have emerged as a sustainable alternative to replace conventional plastics, which constitute a significant portion of accumulated environmental waste. However, compared to petroleum-derived polymers, these materials have some limitations, such as high water solubility, weaker mechanical properties, and lower water vapor and oxygen permeability. Thus, new technologies, such as incorporating nanomaterials like nanocellulose, can help produce stronger CMC materials with improved properties. In this study, CMC films incorporated with eucalyptus (Eucalyptus grandis) nanocellulose at concentrations of 5 %, 10 %, 20 %, and 30 % (relative to the CMC mass) were produced using the casting method. These films were evaluated for solubility, moisture content, water vapor permeability, thickness, optical, mechanical, and thermal properties and biodegradability. FTIR spectra showed molecular and chemical interactions between CMC and nanocellulose. Thickness, moisture content and water vapor permeability remained unchanged, while solubility increased for films with 10 and 20 % of nanocellulose. Young's modulus was improved to 6791.7 MPa in the 30 % nanocellulose film. All samples exhibited four main stages of mass loss 20 °C and 61 °C, 64 °C and 202 °C, 232 °C and 497 °C, 499 °C and 525 °C and also exhibited transparency of about 60 % and low opacity. Furthermore, film ‘s biodegradability was verified and lasted 10 days for films containing nanocellulose. Changes in film properties can be explained by chemical and molecular interactions between CMC and nanocellulose in the films. It is concluded that the addition of nanocellulose is advantageous for improving some characteristics of CMC films.