Studies on the Relationship between the Chemical Structure and the Lightfastness for Disperse and Reactive Dyes with High Lightfatness.

用PM3半经验分子轨道方法考察了一种用于评价多种活性染料感光性能的氨基吡唑基偶氮活性染料与单分子氧的反应位置、反应路径以及典型单偶氮染料的相对反应性；考察了6种单偶氮染料在聚对苯二甲酸乙二酯(PET)和尼龙6薄膜及织物上的有氧和无氧条件下的光褪色行为.这些染料即使在好氧条件下也会发生还原褪色，但有几个例外。用分散染料与乙烯基磺酰化铜络合物染料(CuPc)混合染色的尼龙膜，在曝气或氧气饱和的水中，与不含CuPc的分散染料曝光相比，还原褪色速率降低。CuPc光敏化产生的单线态氧抑制了分散染料的还原褪色。尼龙对联合国…的影响更大根据染料本身的潜在性质，分散染料上的德戈光还原和光氧化作用比PET多。研究了三苯二恶嗪活性染料与乙烯基磺酸基团(PVS-TPDO)和单氯三嗪基团(MCT-TPDO)在水、有机溶剂和纤维素基质上的单体-二聚体平衡。中性电解液的加入促进了PVS-TPDO在水中的聚集，而1-甲基-2-吡咯烷酮(MP)则抑制了PVS-TPDO在水中的聚集。PVS-TPDO在纤维基质上也有聚集现象。干纤维素上的表观K值比水中的小两个数量级，而水中K的表观值增加了约10倍。四种TPDO染料在纤维素和尼龙上的聚集趋势与在水溶液中相同。研究了四种TPDO活性染料在水溶液中与漂白剂次氯酸盐和过氧化氢(HP)在纤维素膜上的反应，并用循环伏安法测定了两种染料的氧化还原电位。在不同的pH值下，TPDO染料与HP在纤维素膜上的反应表现为与HP阴离子的亲核反应，而与次氯酸盐的反应则是与未解离的次氯酸盐发生亲电反应，与次氯酸盐发生亲核反应，尽管TPDO染料之间的相对反应活性主要归因于亲电反应。4，11-双(乙烯基磺酰基)TPDO染料在纤维膜上的次氯酸盐漂白速率小于3，10-双(二取代三嗪基亚甲基)TPDO染料的次氯酸盐漂白速率，而HP漂白速率则相反。较少

Reactivity of an aminopyrazolinyl azo reactive dye, used for the estimation of photosensitivity of many reactive dyes, was examined by PM3 semi-empirical molecular orbital method to show the position of reaction with singlet molecular oxygen, the reaction paths, and the relative reactivity of typical monoazo dyes.The photofading behavior of six monoazo disperse dyes on poly(ethylene terephthalate)(PET)and nylon 6 films and fabrics was examined under aerobic and anaerobic conditions. The dyes underwent reductive fading even under aerobic conditions, with a few exceptions. Exposing nylon films dyed with the disperse dyes in combination with a vinylsulfonyl copper-phthalocyanine dye(CuPc), when immersed in aerated or O_2-saturated water, showed a decrease in the rate of reductive fading compared with exposures involving disperse dyes without CuPc. Singlet oxygen generated by the photosensitization of CuPc suppressed the reductive fading of disperse dyes. Nylon has stronger influence to un … More dergo photo-reduction and photo-oxidation on disperse dyes than PET has, depending upon the potential properties of dye itself. High lightfastness in disperse dyes requires ^1O_2-suppressed photo-reduction due to their self-photosensitization during exposures involving aerobic conditions.Monomer-dimer equilibriums of triphenodioxazine reactive dyes with vinylsulfone anchors(PVS-TPDO)and monochlorotriazine anchors(MCT-TPDO)were investigated in water, in aqueous organic solvent, and on a cellulosic substrate. The aggregation tendency of PVS-TPDO in water was promoted by the addition of neutral electrolyte and suppressed by that of 1-methyl-2-pyrrolidone(MP). PVS-TPDO showed also aggregation on a cellulosic substrate. The apparent value of K on dry cellulose was two orders of magnitude smaller than that in water, and was increased by about ten times by water. Four TPDO dyes examined showed the same order of aggregation tendency on cellulosic and nylon substrates as that in aqueous solution.The reaction of four triphenodioxazine(TPDO)reactive dyes on cellulosic films with bleaching agents, hypochlorite and hydrogen peroxide(HP), was examined in the aqueous solutions and redox potentials for two dyes were measured by cyclic voltammetry. The reaction of TPDO dyes on cellulosic films with HP at different pHs implied a nucleophilic reaction with HP anions, while the reaction with hypochlorite an electrophilic one with undissociated species of hypochlorite and a nucleophilic one with hypochlorite anion, although the relative reactivity among TPDO dyes was attributed mainly to the electrophilic one. The rates of hypochlorite bleaching for 4, 11-bis(vinylsulfonyl)TPDO dyes on cellulosic film were smaller than those for 3, 10-bis(disubstituted triazinyliminoethylimino)TPDO dyes, while the rates of HP bleaching showed the reverse relation. Less