Opto-thermal properties of fibers: XVII. Structure characterization of cold drawn boiled viscose fibers

A two-beam interferometric method is used to study the change of optical pa rameters of cold drawn boiled viscose fibers at different times. A stress-s train device conjugated to the Pluta polarizing interference microscope is used to investigate the dynamical behavior of opto-mechanical properties at room temperature. Some structural parameters such as the number of molecul es per unit volume, the virtual and isotropic refractive indices, the optic al orientation factor and angle, the strain and the stress optical coeffici ents are evaluated. Some mechanical parameters such as, Young's modules, el astic shear modules and the compressibility are calculated over different s train values. Also the number of network chain per unit volume N-c, work pe r unit volume W, average work per chains W', reduction in entropy Delta S, and the optical configuration parameter Delta alpha are determined. Also ca lculation of the constants of Moony-Rivilin equation are given. A systemati c study over different wavelengths range extending from 405 to 590 nm was c arried out to obtain the dielectric constant at infinity. The obtained resu lts clarify that new reorientations occurred due to cold drawing at differe nt conditions. Empirical formula is suggested to correlate the change in De lta n, f(theta), W, W', A, theta, and N-c with different draw ratio, and it s constants were determined. Microinterferograms and curves are given for i llustrations. (C) 1999 John Wiley & Sons, Inc.