Characterization of composite hydrocolloid film based on sodium cellulose sulfate and cassava starch

• The starch was incorporated into cellulose sulfate film to improve water resistance.
• The effects of starch content on mechanical properties and WVP were studied.
• The effects of homogenization temperature for film-forming solution on mechanical properties and WVP were investigated.
• The basic properties of NaCS-starch film such as thickness, water solubility, oil permeability and transparence were report.

The objective of this study was to investigate the effect of the starch incorporation and homogenization temperature on the properties of cellulose sulfate (NaCS)-based films plasticized with glycerol. The film-forming solution, physicochemical microscopic and mechanical properties of films were studied. The SEM of the composite film was more rough than NaCS films, but no signs of phase separation between components were observed. As the starch proportion increased, composite films became more fragile to break, whereas a positive effect on the elasticity of films was realized by a considerable increase in E% values. The composite films presented lower water vapor permeability than films without starch. The temperature for preparation of film-forming solution also had adverse effect on film properties. NaCS film incorporated with 25% starch showed greatly improved resistance to water, though 5% decreasing in TS and small change in other properties compared with NaCS film.