Light‐scattering measurements on selected polyamides (nylons)

Abstract

Abstract A series of polyamides (nylons) formed by polymerizing an aliphatic diamine with an aliphatic acid or by polymerizing an aliphatic amino acid has been investigated by light‐scattering techniques in the solvent 2,2,3,3‐tetrafluoropropanol with 0.1 N sodium trifluoroacetate, as added electrolyte. The series investigated consisted of nylon 6, nylon 66, nylon 610, and Zytel 61. The refractive index gradient ( dn/dc ) for these polyamides was found to be 0.190 cm. 3 /g., and the light‐scattering constant H was taken as 9.59 X 10 −6 cm. 2 ./g. 2 , both values being determined for 4358‐A. incident radiation. Molecular weights, second virial coefficients, and molecular dimensions have been determined for theses polymers.