Combination of beeswax and nanoclay on barriers, sorption isotherm and mechanical properties of hydroxypropyl methylcellulose-based composite films

- Hydroxypropyl methylcellulose (HPMC) has shown a potential as biopolymer films and coatings.
- Clay is a natural nanoparticle and shows good water barrier and mechanical properties in biopolymer films.
- Beeswax (BW) helped reduce water vapor permeability of HPMC-based composite films better than using clay.
- Nanoclay increased the water barrier and likely strengthened the mechanical properties of HPMC-based composite films.
- Combination of BW and nanoclay in HPMC-based composite films was suitable as a biodegradable packaging material.

Hydroxypropyl methylcellulose (HPMC)-based films are widely used but there is still a need to improve their properties due to their hydrophilic nature. Beeswax and nanoclay are generally used as components to increase the water barrier and mechanical properties of biopolymer-based composite films. Thus, the effect of beeswax and nanoclay on the properties of HPMC-based composite films was investigated. It was found that beeswax significantly reduced film water vapor permeability compared to the use of nanoclay. However, beeswax increased film oxygen permeability, compared with nanoclay. Unlike beeswax, the addition of nanoclay increased the water barrier and likely strengthened the mechanical properties (elastic modulus and tensile strength) of HPMC-based composite films, compared with HPMC film. Therefore, the incorporation of both beeswax and nanoclay was suitable to obtain desirable films. Moreover, the HPMC-based composite film can be useful as a biodegradable packaging material to maintain the quality of food products.