Extruded starch foams with polyvinyl alcohol (PVA) are patented by Lacourse et al. [5] and Roesser et al. [6].
Altieri and Tessler [7] patented the water-resistant foams from blends of starch with starch esters. Bastioli et al. [8] patented
foams from blends of starch with 10-30% of polymers such as polyvinyl alcohol (PVA), poly (caprolactone), cellulose
acetate, poly (ethylene vinyl alcohol), and poly (ethylene-co-acrylic acid). Neumann and Seib [9] patented the technology
to make biodegradable starch-based foams using polyglycols