Homogenization mechanism of spinodally decomposed polymer blends via Baker's transformation

An uniaxial compression process is repeatedly applied at room temperature t o homogenize an immiscible polymer blend composed of a random copolymer of poly(styrene-ran-butadiene) and polybutadiene. The different stages of this process are investigated by transmission electron microscopy, laser scanni ng confocal microscopy, and light scattering. The bicontinuous phase-separa ted morphology developed in the as-prepared sample is transformed into a la mellar-like morphology with the lamellar normals preferentially oriented pa rallel to the compression axis upon applying this process. The characterist ic spacing parallel to the compression axis is decreasing constantly, and w hen the spacing becomes smaller than the critical length, the homogenizatio n finally occurs.