Foamable cellulose acetate compositions, foams and foam articles formed therefrom

A foamable composition, comprising:

• (1) a cellulose acetate having a degree of substitution of acetyl (DSAc) between 2.2 to 2.6;
• (2) 5 to 40 wt % of a plasticizer;
• (3) 0.1 to 3 wt % of a nucleating agent;
• (4) 0.1 to 3 wt % a chemical blowing composition, comprises:
• (i) 25 to 75 wt % of a blowing agent, and
• (ii) 25 to 75 wt % of a carrier polymer having a melting point that is no more than 150° C.,
• wherein the proportions of the blowing agent and the carrier polymer are based on the total weight of the chemical blowing composition;
• and
• (5) 0.1 to 25 wt % of a plurality of natural fibers having an average length of 0.1 mm to 15 mm,
• wherein the proportions of the cellulose acetate, plasticizer, nucleating agent, chemical blowing composition, and natural fibers are based on the total weight of the foamable composition,
• wherein the foamable composition is melt-processable, thermoformable and biodegradable.