Biodegradable compositions and articles formed therefrom

A foamable composition comprising:

• (a) a cellulose ester which is a cellulose acetate propionate (“CAP”);
• (b) a biodegradable polymer which is a polyester;
• and
• (c) a blowing agent,
• wherein the polyester is chosen from poly(butylene succinate) (“PBS”), poly(butylene succinate adipate) (“PBSA”), polycaprolactone (“PCL”), poly(butylene adipate terephthalate) (“PBAT”), or combinations thereof,
• wherein the biodegradable polymer is present at from 1 wt % to 30 wt % based on the total weight of the cellulose ester and the biodegradable polymer,
• wherein the CAP has an average degree of substitution for hydroxyl substituents that is from 0.3 to 1.2, an average degree of substitution for the acetyl substituents (“DSAc”) that is from 0 to 0.5, an average degree of substitution for the propionyl substituents (“DSPr”) that is from 1.3 to 2.5, and a ball drop viscosity of from 0.1 to 30 as measured according to ASTM D-1343,
• wherein the composition has a reduced blowing agent diffusion of at least 10% as compared to the composition without the biodegradable polymer.