Effect of a natural polyphenolic extract on the properties of a biodegradable starch-based polymer

A polyphenol-containing extract from winery bio-waste (EP) has been used as an additive for a starch-based polymer (Mater-Bi). EP was used to tailor Mater-Bi properties, thus avoiding the use of synthetic polymer additives. It was found that EP was able to efficiently modulate the processing, mechanical, thermal and biodegradation properties. The observed decrease in melt viscosity showed that EP could improve productivity in polymer processing. Owing to the plasticizing activity of the additive, larger values of elongation at break were found. Moreover, the Mater-Bi crosslinking, which occurs upon thermal aging, was delayed in the presence of EP. Finally, the bio-disintegration rate of doped Mater-Bi decreased, thus suggesting that EP acted as an antimicrobial agent by interfering with the bio-digestion of the polymer films. (C) 2011 Elsevier Ltd. All rights reserved.