Biodegradable thermoplastic mixture of starch ester and poly alkylene glycol

摘要

A biodegradable, thermoplastically formable material contains starch esters and plasticisers. The starch esters are based on starch containing 20-80 mass% of amylopectin, and have a substitution degree of less than 3. Polyalkylene glycol(s) of MW 200-2,000 are present in a ratio of starch ester/polyalkylene glycol of 10:1 to 10:5. Optionally 20-80% of the polyalkylene glycol can be replaced by a polyhydroxybutyric acid having a MW of 1,000-10,000 and/or the blend can contain an aliphatic (un)saturated dicarboxylic acid, hydroxycarboxylic acid or hydroxytricarboxylic acid with 2-10C atoms in a ratio of blend/acid of 100:1 to 1,000:1.