Patent ID: 7431875

Claim:
A process of preparing a unitized membrane electrode assembly using compression molding comprising: (a) forming a multilayer sandwich comprising a first gas diffusion backing having sealing edges; a first electrocatalyst coating composition; a polymer membrane; a second electrocatalyst coating composition; and a second gas diffusion backing having sealing edges; and (b) compression molding a sealing polymer to the multilayer sandwich, wherein the mold used in the compression molding apparatus comprises: (c) a frame part with a hole through its center; (d) a bottom plunger; and (e) a top plunger; wherein the plungers are fabricated to fit substantially snuggly in the hole in the frame part, and wherein at least one plunger comprises at least one low-thermal conductivity insert; whereby the sealing polymer is impregnated into at least a portion of the sealing edges of the first and second gas diffusion backings, and the thermoplastic polymer envelops a peripheral region of both the first and second gas diffusion backings and the polymer membrane to form a thermoplastic polymer, fluid impermeable seal.