Properties of hydrophobic enhanced biodegradable starch / PVA films

The hydrophobic enhanced biodegradable films of corn-starch, polyvinyl alcohol, epoxide-modifying polyamide(EPA), and alkyl ketene dimer (AKD) were prepared by solution casting. The dynamic contact angle and water absorption analysis show that the hydrophobility of the SP film is increased by the addition of AKD. When the content of AKD is 3.30%, the contact angle and water absorption rate of the film reaches 90° and 15.44%, respectively. EPA can improve the tensile strength obviously, while it is disadvantageous to the breaking elongation of the SP film when the content of EPA is exorbitant. X-ray diffraction indicates the compatibility between the film components is increased by the internal plasticizing effect of AKD and the crosslinking of EPA. Testing biodegradation activity shows that both St.aureus and E.coli have some biodegrading abilities on the SP films. However, the biodegradation ability of the SP films reduces with increasing of EPA content.