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Photoresponsive polyurethane–acrylate block copolymers. I. Photochromic effects in copolymers containing 6′‐nitro spiropyranes and 6′‐nitro‐bis‐spiropyranes
Author(s) -
GonzalezDe Los Santos Eduardo A.,
LozanoGonzález Ma. Josefina,
Johnson Anthony F.
Publication year - 1999
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19990110)71:2<259::aid-app9>3.0.co;2-u
Subject(s) - copolymer , photochromism , nitro , photoisomerization , polyurethane , acrylate , polymer chemistry , materials science , photochemistry , chemistry , polymer , organic chemistry , isomerization , catalysis , composite material , alkyl
The photochromic effect of polyurethane–acrylate block copolymers containing 6′‐nitro spiropyranes and 6′nitro‐bis‐spiropyranes has been investigated. The influence of incorporation of the photochromic agent into the polymeric matrix as a simple solid solution or in a chemically bonded form and the effects of the composition (polyurethane–acrylate) of the block copolymer were studied. In general, it was observed that the photoresponse for the spiropyranes and especially the bis‐spiropyranes obey the combination of several factors, mainly the spatial and electronic differences between the two forms (Sp.–Mer.) in the photoisomerization of these compounds. Such factors are discussed here. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 259–266, 1999