Which term describes a heterogeneous system comprised of not less than two phases, one of which is a continuous polymeric, organic material, and the second introduced to distribute gas in voids?

• A. Cellular Plastic
• B. Cellular or Foamed Plastic
• C. Foam Rubber Insulation
• D. Composite Foam Metal

Answer: (B)

The material described is a two-phase system where one phase is the continuous polymeric organic matrix and the second phase is gas distributed in voids, forming cells. When a blowing agent is introduced, gas creates numerous cavities inside the polymer, producing a cellular structure. This combination—a polymer matrix with gas-filled cells—defines cellular or foamed plastic. The term explicitly captures both the solid polymer network and the dispersed gas-filled voids, which is why it’s the best descriptor. Other terms refer to specific forms (like foam rubber) or different materials (like metal foams) that don’t match the general polymeric foamed structure described.