Immiscible blends of cellulose acetate butyrate (CAB) and poly(trimethylene terephthalate) (PTT) were melt extruded through a two strand rod die. The extrudates were hot-drawn at the die exit at different draw ratios. PTT fibers were obtained by removal of the CAB matrix from the drawn extrudates, and the morphology evolution of the formed fibers was investigated by scanning electron microscopy. PIT nanofibers with an average diameter of 55 nm were produced by controlling the drawing ratio. (C) 2010 Elsevier B.V. All rights reserved.