Abstract: For converting native starch or starch derivatives into thermoplastic starch, added to the starch is at least one hydrophobic biodegradable polymer. This hydrophobic biodegradable polymer, which serves as a plasticizer or swelling agent, may be a polymer selected from the following list: an aliphatic polyester, a copolyester with aliphatic and aromatic blocks, a polyester amide, a polyester urethane, a polyethylene oxide polymer and/or a polyglycol, and/or mixtures of these. When the starch, such as in particular native starch or derivatives thereof, is mixed in the melt with the hydrophobic biodegradable polymer as a plasticizer or swelling agent, to homogenize the mixture, the water content is reduced to <1% by weight based on the weight of the mixture.
Type:
Grant
Filed:
December 18, 1998
Date of Patent:
May 22, 2001
Assignee:
Bio-tec Biologische Naturverpackungen & Co. KG
Inventors:
Jurgen Loercks, Winfried Pommeranz, Harald Schmidt, Ralf Timmermann, Ernst Grigat, Wolfgang Schulz-Schlitte