Breathable and biodegradable film has packaging potential

01 Nov 2011

A synthetic, biopolymer-based biodegradable and breathable food packaging film has the potential to solve waste packaging problems, according to new Czech research.

The study, 'Biodegradable Hydrogel Film for Food Packaging', investigated the development a breathable hydrogel film for food application using synthetic polvinylpyrrolidone (PVP) and biopolymers carboxymetyl cellulose (CMC) to create a PVP-CMC hydrogel film.

Researchers Niladri Roy, Nabanita Saha and Petr Saha investigated the biodegradeability of such film in work done at the Centre of Polymer Systems at the Tomas Bata University in Zlin, the Czech Republic.

Through their work, the scientists concluded that PVP-CMC hydrogel film was breathable and completely biodegradable, and was therefore well-suited for food packaging applications. According to the study, the transparent and flexible film “seems promising as a food packaging material and to meet up to a certain limit the challenges raised by environmental pollution created by plastic waste materials.”

Breathable and biodegradable

The study said: “Special attention was given for the breathability of the hydrogel films, as some food materials, mainly fresh vegetables need aeration, i.e. flow of oxygen to maintain their freshness.”

“The results obtained from this research investigation on PVP-CMC hydrogel film successfully prove that the PVPCMC hydrogel film is breathable and on the other hand completely biodegradable. The film is transparent and flexible too.”

Water vapour transmission (WVP) testing proved the constant aeration rate of the hydrogel film and a biodegradability study of the PVP-CMC films was carried out.

Researchers conducted a soil burial-test in a controlled compost environment, where the total time of biodegradation was five weeks with no significant hydrogel film residue after that.

During this time structural deformation and weight loss of the film were studied weekly.

Promising food packaging material

Hydrogel characteristics such as transparency, good oxygen barrier properties and low cost make them one of the most in-demand materials for food packaging, the researchers said.

Most plastic food packaging materials are non-degradable and the use of biodegradable polymers has been limited because of performance problems.

“This is important, because some food materials release moisture, and that should be absorbed by the packaging materials to avoid the food from fast decay,” the authors said.

“The most important parameter is the bio-degradability of the packaging material to avoid environmental hazards,” they added.

"As a whole this PVP-CMC hydrogel film seems very promising as a food packaging material and to meet up to a certain limit the challenges raised by environmental pollution created by plastic waste materials.”

Source: Tomas Bata University