Opto-mechanical properties of fibres. Part 1. Optical properties and orientation of drawn polyethylene fibres

✍ Scribed by Fouda, IM; Shabana, HM

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 291 KB
• Volume: 48
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199903)48:3<181::aid-pi135>3.0.co;2-v

✦ Synopsis

Changes in the structure of diþ erent drawn polyethylene (PE) übres are studied by the Becke' line method and interferometrically. The Becke' line method is used to study the changes in the optical properties of the skin layer of PE undrawn übres. A Pluta polarizing interference microscope is used to determine the mean refractive indices and mean birefringence of the drawn übres. Some structural parameters, such as optical orientation function, electric polarizability diþ erence and isotropic polarizability are determined. This last parameter is found to be constant and depends (Da/3a 0 ), only on the übre structure. The number of molecules per unit volume and the distribution of segments at an angle with respect to the draw ratio are also determined. The generalized Lorentz-Lorenz equation given by de Vries is used to determine PE übre structural parameters. A comparison between the experimental and those obtained using the Lorentz-Lorenz equation is given. A refractive index proüle can assist übre characterization. An empirical formula is suggested to correlate the changes in A, Dn, and h with the draw ratio, and its constants are determined. Microinterferograms f h and curves are given for illustration.