BIODEGRADABLE COMPOSITIONS COMPRISING STARCH AND POLYSACCHARIDE ESTERS

摘要

The biodegradable heterophase compositions comprise partially or completely destructurized and/or complexed starch, a polysaccharide ester and a plasticizer for the polysaccharide ester. In these compositions, the polysaccharide ester constitutes the matrix and the starch the dispersed pha se in the form of particles or domains of numeric mean dimension lower than 1 .mu.m and preferably than 0.5 .mu.m for at least 80 % of the particles. The compositions also comprise an additive which can increase and maintain at values of 4 or more the pH of a solution obtained by placing the composition s in pellet form in contact with water at ambient temperature for 1 hour, with the use of a pellet:water ratio of 1:10 by weight.