In cocontinuous blends of immiscible polymers both phases are continuously connected throughout the structure. Due to their microstructure, these blends lend themselves to a variety of applications from mechanically robust conductive polymer blends1 to porous polymers if one phase is extracted2 and even to razor blade lubricating strips.3 These blends are thermodynamically unstable, and unless they are compatibilized will coarsen during annealing. Controlling the size of blend features and the compositions which can produce cocontinuity is critical for product design. This is especially true for porous materials derived from cocontinuous blends, as the domain size and volume fractions of the materials determine the pore size and porosity of the final product. Blends were prepared by melt mixing and their morphology was analyzed gravimetrically via solvent extraction4, and imaged by scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM), the latter of which was used to generate 3D reconstructions of the cocontinuous microstructure for characteristic size analysis.5 The minimum volume fraction required to create cocontinuity appears to be governed by interfacial tension, mixing and component rheology, particularly extensional rheology.6 For all blends coarsening is controlled by the ratio of interfacial tension over log average of the zero shear rate viscosity. Coarsening can be arrested by adding block copolymers7,8 or particles9,10 which go to the interface or by reactive coupling between component polymers across the interface.3 New macro and micro porous materials have been created from blends of three components. Keywords: compatibilization, interfacial tension