Patent ID: 7872056

Claim:
A bio-based or partially biodegradable thermoplastic foam structure comprising a blend, said blend comprising: at least one alkenyl aromatic polymer in the amount between about 10 to 90 percent by weight of the blend; at least one bio-based or biodegradable polymer selected from polylactic acid and copolymers thereof or polyglycolic acid and copolymers thereof in the amount between about 10 to 90 percent by weight of the blend; and at least two blend compatibilizers comprising a first blend compatibilizer selected from the group consisting of styrene-ethylene-butene-styrene and maleated styrene-ethylene-butene-styrene and a second blend compatibilizer selected from the group consisting of styrene-maleic anhydride copolymer and styrene-methyl methacrylate copolymer, wherein the foam structure comprises at least about 1 percent by weight of the first blend compatibilizer and at least about 2 percent by weight of the second blend compatibilizer, and up to about 10 weight percent of the at least two blend compatibilizers collectively, and further wherein the foam structure is a thermoformable sheet having expansion ratio greater than 7.