2,2-二烷基-2-烷胺基苯乙酮/二芳基酮复合引发体系光聚合的加和作用

本文研究了2,2-二烷基-2-烷胺基苯乙酮(α-AK)和二芳基酮(DAK)(包括二苯酮(BP)、米酮(MK)、二乙基蒽醌(EAQ)和硫杂蒽酮(TX))复合体系的加和作用。体系中DAK的添加显着地改善了α-AK在近紫外光区长波段无吸收的缺陷。光聚合实验比较了DAK的效果,其中氯代TX、BP增效作用显着,使聚合反应速度增加1.3～1.5倍,而MK和EAQ没有明显影响。同时还研究了溶剂极性、浓度和取代基的影响。结果表明,溶剂极性增加起负影响,α-AK/DAK等摩尔浓度效果最佳和氯代TX活性高于烷基取代TX.通过吸收光谱α-AK/DAK复合体系的加和作用机制进行了研究,结果证明三重态的能量传递敏化反应和光还原反应两种反应过程并存,它们的贡献因二芳酮不同而有差异。

SYNERGISTIC EFFECTS OF 2,2 DIALKYL 2 ALKYLA MINOACETOPHENONE/DIARYLKETONE COM BINATION PHOTOINITIATION SYSTEM

The synergistic effects of combination photoinitiation system composed of 2,2-alkyl-2-alkylaminoacetophenone (α-AK) and diarylketone (BP, MK, EAQ and TX) were studied. Addition of diarylketone to α-AK significantly improved the absorption at long wavelength near UV region. Effects of different diarylketones on photopolymerization were compared. Among these, CTX and BP are superior to other compounds and give an increase of polymerization rate by a factor of 1.3-1.5, whereas MK and EAQ have no distinct influence. Effects of solvent polarity and concentration were also studied. The results indicate that the increase of solvent polarity has a negative effect, the excellent effect is approached when α-AK and DAK are equimolar, and the reactivity of chlorothioxanthones (CTX) is higher than that of other alkylthioxanthones (ITX, DETX). The mechanism of synergistic effects of α-alkylaminoacetophenone and diarylketone was investigated by absorption spectra and the results demonstrate that the two different mechanisms, triplet energy transfer sensitization and photoreduced reaction, exist and their attributions depend on the different diarylketones.