基于光致脱羧的双光子聚合引发剂的制备及结构-性能研究

Back electron transfer significantly decreases the initiation rate of two-photon polymerization. Such issue has not been addressed from the aspect of mechanism. In order to explore two-photon induced decarboxylation，a new initiation mechanism for two-photon polymerization, a series of novel two-photon initiators containing terminal N-phenylglycine groups are proposed. The detailed information of the mechanism can be elucidated by systematic investigating the effect of molecular structures on the decarboxylation rate and analyzing the photolytic products.The influence of the mechanism on the initiation rate will also be studied. The proposed mechanism is aimed at effectively suppressing the back electron transfer and therefore increasing the initiation efficiency. Such mechanism would become an alternative of new strategy for the design of potent two-photon initiators.

逆电子转移可显著降低双光子聚合的引发速率，该问题一直未能从机理上加以解决。本项目拟通过设计和合成一系列含N-苯基甘氨酸端基的新型双光子引发剂来探索一种新的聚合引发机理——双光子光致脱羧。通过系统考察引发剂分子结构对光致脱羧速率的影响，剖析光解产物，力图阐明光致脱羧的反应历程，并研究该反应对聚合引发速率的影响。旨在通过该机理有效抑制逆电子转移，提高双光子引发活性，为高效双光子引发剂的分子设计提供一种新策略。

不可逆的光致脱羧反应可有效抑制逆电子转移，从而提高双光子引发剂的引发活性。基于此机理，本项目设计并合成了一系列具有光致脱羧性质的光引发剂分子，并通过激光闪光光解、电子自旋共振等方式对光致脱羧过程进行了定性和定量研究，阐明了光致脱羧机理，确定了影响光致脱羧效率的关键分子结构，并证明了光致脱羧型引发剂分子的引发活性高于存在逆电子转移的双组分引发体系。该类引发剂分子可有效引发自由基聚合，通过飞秒激光微加工技术可筑精细的三维微纳结构。在机理研究的基础上，进一步通过分子设计，制备了一系列高效的光产碱剂和混杂光引发剂，并探索了其在巯基-环氧及巯-炔-环氧体系的应用。