Carboxymethyl
cellulose (CMC) has attracted considerable
interest
in research due to its exceptional film-forming properties and compatibility
with biological systems. However, CMC films still suffer from mechanical
brittleness and structural instability due to the rigid structure
and many hydroxyl groups in practical applications. Herein, a nanocomposite
film is reported, synthesized via inserting layered montmorillonite
(MMT) into a CMC and guar gum (GG) hydrogen bond networks. Incorporating
MMT with a high aspect ratio increases the number of hydrogen bond
cross-linking sites among constituents, thereby enhancing the mechanical
strength and toughness of nanocomposite films. The resulting CMC/GG10/MMT6 films show flexibility (elongation at break
83.5 ± 4.35%), high tensile strength (53.5 ± 1.10 MPa),
and high toughness (32.16 ± 1.04 MJ/m3). These films
also integrate hydrophobic (up to 84.78°) and high-temperature
resistance (50% degradation temperature up to 304 °C) properties
to adapt to complex practical application environments. Moreover,
they exhibit excellent ultraviolet shielding performance under a wide
wavelength range (200–320 nm). Soil burial experiments showed
that all the films could be assimilated into the soil within about
9 days. This approach offers a simple and promising route for producing
biodegradable CMC-based films for food packaging.