Opto-thermal properties of fibers - 7. Different annealing effects on someoptical structural variations of nylon 66 fibers

Two-beam interferometry and density methods previously described are used t o study the changes in optical properties of nylon 66 fibers annealed and q uenched in coarse ice at temperatures 90-180 +/- 1 degrees C for 6 h. Some structural parameters are determined in the present work such as the form b irefringence (Delta n(f)), the number of molecules per unit volume, the vir tual refractive index, the harmonic mean polarizability of the dielectric, the harmonic mean specific refractivity, the number of monomer units per un it volume. The generalized Lorentz-Lorenz equation given by de Vries is use d to determine annealed nylon 66 fibers structural parameters. Comparisons between the results and when using Lorentz-Lorenz and Hermans equations are given. (C) 1999 Elsevier Science Ltd. All rights reserved.