18—THE DEGREE OF POLYMERIZATION AND ITS DISTRIBUTION IN CELLULOSE RAYONS: Part VIll.—THE INFLUENCE OF DEGREE OF POLYMERIZATION AND MOLECULAR ORIENTATION ON THE MECHANICAL PROPERTIES OF MOLECULARLY-HOMOGENEOUS MONOFILAMENTS

Molecularly-homogeneous fractions of secondary cellulose acetate DP 100—800) were spun by a wet-spinning technique into monofilaments; the filaments were stretched to produce different degrees of orientation, and then saponified to cellulose filaments. The birefringence of the filaments was measured and used as an index of orientation; the tenacities and breaking extensions were determined with a Cambridge extensometer. Some measurements were also made on cellulose acetate filaments. By taking into account molecular orientation, it is shown that degree of polymerization is a much more important factor influencing the properties of rayons than previous published work with films has suggested.