Hydrophobicity Improvement of Corn Starch / Bovine Gelatin BlendBiofilms
FoadHossein Abad Farahani, Abbas Sheikh[1]
Polymer Engineering Department, Faculty of Chemical Engineering, TarbiatModares University, P.O. Box: 14115-114, Tehran 1411713116, I.R. Iran
Starch was chemically modified through reactive extrusion with paraffin (P) as well as anhydride acetic (AA) to decrease its hydrophilicity and improve processability. Then, it was blended with starch/gelatin. All blendsplasticized with water and sorbitol. Afterwards, the compounds were processed to form edible biofilms. These were done within a Brabender laboratory counter rotating twin screw extruder. The resultant 350µm thick films were assessed in terms of tensile properties, contact angle, water absorption and water vapor permeability (WVP) to compare starch-g-P/starch/gelatinand also starch-g-AA/starch/gelatin ternary plasticized blends with starch/gelatin blend.
Results show that blending plasticized starch with gelatin increased hydrophobicity and led to much better film forming properties. Introducing starch-g-P and Starch-g-AA to starch/gelatin blend improved processability besides further hydrophobicity. Contact angleof blends containingstarch-g-P was more than those having starch-g-AA and both are more than neat starch/gelatin blend. Also, tensile strength of starch-P/starch/gelatinblendis about 13% more than the starch/gelatin, but that of starch-g-AA/starch/gelatin did not change appreciably in addition to lowest elongation at break.Retrogradation and aging effects on tensile properties have been also investigated.WVP and water absorptionresults are in general agreement with contact angle test.
According to this study, both binary and ternaryblends of starch/gelatinarepromising as a biobased, biodegradable film with controllable hydrophilic properties and processability.
Biography
Abbas Sheikh has completed his PhD at the age of 31 years from Amirkabir University of Techology. He is a member of Chemical Engineering Faculty of TarbiatModares University in Iran. Hiscurrent research interest is focused on biopolymeric blends.
[1]Corresponding author.Phone: + 98 21 82884354.
Email addresses: (F.H.Farahani), (A. Sheikh)