Abstract: A method of producing a foamed material comprises contacting a mixture comprising a first thermoplastic polymer and a second thermoplastic polymer with a blowing agent, wherein the first thermoplastic polymer has a higher percent crystallinity that the second thermoplastic polymer; and subjecting the mixture to conditions sufficient to create a thermodynamic instability in the blend foam the mixture, wherein the mixture comprising the first and second thermoplastic polymers has a percent crystallinity lower than the first thermoplastic polymer.