Abstract: Soybean dregs/starch composite films were prepared by soybean dregs and starch as raw material with glycerin and sodium hydroxide as solvent in fusion method. The mechanical properties and the solution viscosity of the composite films were also investigated. The effects of the concentration of NaOH, ratio of soybean dregs /starch and the content of glycerol on the melt viscosity and breaking strength of the composite film were studied by adopting twice common rotation combined design and experiment scheme. Results showed that the addition of NaOH and the ratio of soybean dregs/starch are important factors affecting the film-forming of composite films. When the concentration of NaOH was 17%, the ratio of soybean dregs/starch was 1.135 and the content of glycerol was 0, the solution viscosity of the composite film could be best as 6.25kpa?s and its breaking strength of the film was better than common film as 4.21Mpa. The addition of glycerol is suggested to improve the friability of composite films.

Key words: soybean dreg, starch, compwsite film, viscosity, breaking strength