On the Photodegradation of Some 2<i>H</i>-Chromene Derivatives in Fluid Solution or in Polyurethane Matrix
作者:Angelo Alberti、Mylène Campredon、Renaud Demadrille
DOI:10.1246/bcsj.20100338
日期:2011.5.15
The time profile of the optical density was monitored during the photodegradation of three derivatives of 2,2-diphenyl-2H-naphtho[1,2-b]pyran (1), namely 2,2-bis(4-methoxyphenyl)-5,6-dimethyl-2H-naphtho[1,2-b]pyran (2), 2,2-diphenyl-5-[(ethoxycarbonyl)methoxycarbonyl]-8-methyl-2H-naphtho[1,2-b]pyran (3), and 3,3-bis(4-methoxyphenyl)-6,11-dimethyl-13-hydroxy-13-isopropyl-3H-indeno[2,1-f]naphtho[1,2-b]pyran (4) either in toluene solution or in a polyurethane matrix. The photoproducts were identified using HPLC, GC/MS, and direct insertion MS techniques. High molecular weight oxygenated derivatives and new photoproducts deriving from a secondary oxidative pathway were characterized along with expected degradation derivatives. Some of the photoproducts considered responsible for the yellowing of the examined materials were identified. The effect exerted by two additives generally considered to have an inhibiting action toward radical processes was also evaluated.
在 2,2-二苯基-2H-萘并[1,2-b]吡喃(1)的三种衍生物,即 2,2-双(4-甲氧基苯基)-5,6-二甲基-2H-萘并[1,2-b]吡喃(2)、2、2-二苯基-5-[(乙氧基羰基)甲氧基羰基]-8-甲基-2H-萘并[1,2-b]吡喃(3),以及 3,3-双(4-甲氧基苯基)-6,11-二甲基-13-羟基-13-异丙基-3H-茚并[2,1-f]萘并[1,2-b]吡喃(4)的甲苯溶液或聚氨酯基质。利用高效液相色谱、气相色谱/质谱和直接插入质谱技术对光衍生物进行了鉴定。高分子量含氧衍生物和来自二次氧化途径的新光产物以及预期的降解衍生物都得到了鉴定。确定了一些被认为是造成受检材料变黄的光反应产物。此外,还评估了两种通常被认为对自由基过程具有抑制作用的添加剂的效果。