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UV polarizers based on oriented poly(vinyl alcohol)–Chrysophenine–Congo red blend films

✍ Scribed by Elissa Beekman; Christoph Kocher; Akshay Kokil; Sven Zimmermann; Christoph Weder


Publisher
John Wiley and Sons
Year
2002
Tongue
English
Weight
94 KB
Volume
86
Category
Article
ISSN
0021-8995

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✦ Synopsis


Abstract

The availability of efficient low‐cost ultraviolet (UV) film polarizers is of vital importance to a number of applications, which rely on the use of polarized light in the near‐UV regime. We describe here the preparation of such elements based on stretch‐oriented films comprising poly(vinyl alcohol) and a combination of two commercially available azo dyes, Congo Red and Chrysophenine. Films of various dye contents were prepared and oriented by uniaxial tensile deformation. Moderately stretched films (draw ratio l/l~0~ = 4–8) exhibit a pronounced optical dichroism, characterized by a polarizing efficiency up to 0.98 at a wavelength of 365 nm. Initial experiments suggest that, even under rather harsh irradiation conditions and without any packaging, these azo‐dye‐based polarizers are surprisingly inert under simulated operating conditions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1235–1239, 2002