Blend modification of feather keratin‐based films using sodium alginate

ABSTRACT Feather keratin (FK), which can be extracted from waste feathers, is a kind of biodegradable and renewable protein resource and it has a great potential in the field of materials such as keratin sponges, films, and microcapsules. The aim of the current study was to investigate the blend modification of FK‐based films using sodium alginate (SA). A series of FK‐based films blended with different ratios of SA were prepared by the casting process. The cross‐section of blend films had a compact and homogeneous structure and no distinct phase separation was observed, indicating the favorable compatibility between FK and SA. The result of DSC analysis, in which there was a change in crystal structure, confirmed the interaction between FK and SA in the blend films. The FTIR spectra pointed out that the main interaction between the two components would be through the formation of hydrogen bonds. The incorporation of SA to FK significantly enhanced the strength and maintained the extensibility of the resultant films. The water vapor permeability reached its lowest level when the ratio of FK to SA was 7:3. Moreover, the blend films exhibited a relatively high level of transparency with SA content below 30%. These improvements by incorporation of SA provided the potential to expand the application of FK‐based films in packing and bio‐medical industries. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44680.