Background: composite films which are consisted of edible and synthetic components are introduced as a novel idea in food packaging industry. Because of different nature of these components, it is problematic to use them in a composite film without any modification on polymer surface. In this study, plasma treatment was used to modify polypropylene (PP) surface and then it was coated by carboxymethyl cellulose (CMC). 

Material and methods: In this study, physical, mechanical and water vapour permeability of bilayer films (PP/CMC) were compared with individual PP and CMC films. In order to perceive the effect of plasma treatment on the properties of bilayer films, a comparison was also done between treated and untreated bilayer films.

Results: Plasma treated PP/CMC films had lower water vapour permeability and better mechanical properties compared to untreated bilayers, individual PP and CMC films.

Conclusion: Application of plasma treated PP/CMC films could have an important role in improvement of barrier and mechanical properties of food packaging.