曙红染料-碘鎓盐复合体系的光化学性质和引发丙烯酸酯光交联的效果

合成了曙红(EO)二苯基碘鎓盐(DPIO)复合光引发体系,其光响应范围可至可见光区,最大吸收527nm。曙红鎓盐体系无暗反应,但在可见光作用下,由于光诱导电子转移敏化反应使染料发生漂白作用和鎓盐裂解产生活性自由基,由此可引发环氧6101双丙烯酸酯和季戊四醇三丙烯酸酯的光固化。光固化速度与复合体系的结构组成有关,其中曙红双盐(EO(Ph_I)_2)比曙红单盐(EO(Ph_2I))具有更高的引发效率;在同样条件下双分子体系(EONa_2+Ph_2I+BF_4~-)不能引起交联反应。

PHOTOCHEMICAL CHARACTERISTICS AND PHOTOCROSSLINKING EFFECTS OF EOSINIODONIUM SALT ON ACRYLATES

Eosin dye (EO)-diphenyliodonium salt(DPIO) system has been synthesized as a new dye photoinitiator sensitive to visible spectral region. Its maximum absorption is at 527nm. The eosiniodonium system does not react in the dark .but on irradiation with visible light,the photoinduced electron transfer sensitive reaction may lead to the bleaching of dye and cleavage of iodonium. The produced free-radicals could initiate the curing of acrylate film composed of epoxy 6101 diaerylate and pentaerythritol triacrylate (2:1 W/W). The photocuring rate was found to be depended strongly on the composition of the system. The diiodonium salts EO (Ph_2I)_2 appeared more effective than monoiodonium salt EOEt (Ph_2I), while the bimolecular system (EONa_2+Ph_2I~+BF_4~-) failed to cause any crosslinking reaction in the same coudition. It may be concluded that the photoinduced electron transfer photosensitization by the ion-pairs is a high efficient pathway to overcome the diffusion controlled limitation.