Preparation and Physicochemical Properties of Dialdehyde Starch Crosslinked Feather Keratin/PVA Composite Films

Feathers, as a by-product of the poultry industry, have long been treated as solid waste disposal which causes a series of environmental and economic problems. Feather keratin (FK) can be extracted from feathers and have very strong stretching resistance. A series blend films based on FK and poly (vinyl alcohol) (PVA) was prepared by solution casting, and dialdehyde starch (DAS) were introduced to achieve better physicochemical properties for the blend films. According to DSC analysis, the single glass transition temperature and single melting temperature of the blend films indicated the good compatibility among FK, PVA and DAS. With increasing PVA content, the tensile strength (sigma(b)), elongation at break (epsilon(b)), and decomposition temperature increased, indicated that hydrogen bonds were formed between FK and PVA. With certain PVA content, the increase of DAS caused sigma(b) to increase and epsilon(b), decomposition rates, solubility and water vapor permeability (WVP) to decrease, suggesting the formation of crosslink network among FK, PVA and DAS, that is to say, the mechanical properties, thermal stability and water-resistance of FK/PVA blend film were improved by crosslinking with DAS. The blend film was uniform and translucent, and could be used in packing and bio-medical industries.