| 摘要 |
A biodegradable polymer is disclosed having the composition g) from 8 to 80% by weight of a starch modified to include an hydroxyalkyl C<SUB>2-6 </SUB>group or modified by reaction with an anhydride of a dicarboxylic acid, preferably hydroxypropylated high amylose starch, a) from 0 to 87.9% of starch, b) from 4 to 11% by weight of a water soluble polymer selected from polyvinylacetate, polyvinyl alcohol and copolymers of ehtylene and vinylalcohol which have a melting point compatible with the molten state of the starch components, c) from 0 to 20% by weight of a polyol plasticiser, preferably glycerol, d) from 0.1 to 1.5% by weight of a C<SUB>12-22 </SUB>fatty acid or salt, preferably stearic acid and, e) 0 to 12% added water. The polymers are suitable as biodegradable rigid sheet or flexible film materials for use in packaging foodstuffs.
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