Each homopolymer, cellulose and polyamide 66 (PA66), was separately dissolved in a mixture of N-methyl morpholine N-oxide and phenol (80/20 w/w). Then, the two solutions were mixed together. This step leads to the crystallization of PA66 in small aggregates (about 1 μ) regularly dispersed in the cellulose solution. It appeared that this morphology remains independent of further processing such as spinning or casting. Finally, fibers or films were precipitated in methanol. The entire preparation technique used here results mainly in two-phase systems in which PA66 domains are embedded in an amorphous cellulose matrix. The specimens obtained were at first characterized by differential scanning calorimetry, scanning electron microscopy, and wide angle x-ray scattering. © 1994 John Wiley & Sons, Inc.