The fine structures

paracrystal

porous and phase structures of blend acrylic fibers have bencharacterized using techniques based on X-ray diffraction

gas adsorption

density

electron and opticalmicroscopy

mercury penetration method and IR spectroscopic analysis. The existence of a fibril-void structure

with voids and fibrils of the order of 102.to 103A diameter has been confirmed for thewet-spun blend fibers. It was found that the blend acrylic fiber in the present work is a kind of ma-trix-fibril fiber;phase separation takes place in it.Further studies about the effects of composition and sequence distribution of copolymers on structure of the blend fibers were made;and it was discovered that void volume in the blend fibers largely depends on the interface area between two polymer phases

and pore size and number on the particle size and number of the dispersing phase.An appropriate structural model about the blend fibers has been described.