New kinetic and mechanistic aspects of photosensitization of iodonium salts in photopolymerization of acrylates
New kinetic and mechanistic aspects of photosensitization of iodonium salts in photopolymerization of acrylates
复制标题
DOI：
10.1039/c7ra05978g
复制
发表时间：
2017-01-01
期刊：
影响因子：
3.9
通讯作者：
Kostrzewska, Katarzyna
中科院分区：
文献类型：
--
作者：
Kabatc, Janina;Ortyl, Joanna;Kostrzewska, Katarzyna
介绍了一种电子转移光敏剂1,3-双（对溴苯胺）方卡因在紫外蓝光照射下的三丙烯酸酯聚合自由基光引发剂。光敏剂的功能由合适的共引发剂的存在决定。为此，几种不同的二苯硫鎓盐被用作自由基聚合的活性物质来源。以方碱染料为增感剂，采用紫外蓝光引发自由基聚合，用dsc法研究了新碘盐的反应性。碘盐作为自由基引发剂具有不同的取代模式。从敏化剂的激发态到碘盐的电子转移导致引发自由基。所研究的碘盐引发TMPTA自由基聚合的能力是相似的。大多数碘盐在引发TMPTA聚合的反应性方面没有太大的差异。然而，在共引发剂苯环的对位上引入硝基会导致聚合速率和单体转化率的显著增加。证实了SQ/I体系的染料敏化光反应机理。
1,3-Bis( p-bromophenylamino) squaraine which functions as an electron-transfer photosensitizer for a wide range of diphenyliodonium salts radical photoinitiators of triacrylate polymerization under UV-blue light irradiation is presented. The functionality of the photosensitizer is determined by the presence of a suitable co-initiator. For this purpose, several different diphenyliodonium salts were used as a source of active species for radical polymerization. The reactivity of the new iodonium salts was studied with ultraviolet-blue light initiated radical polymerization by photo-DSC using squaraine dye as a sensitizer. The iodonium salts functionated as radical initiators bearing different substitution patterns. Electron transfer from the excited state of the sensitizer to the iodonium salt results in initiating radicals. The ability to initiate free radical polymerization of TMPTA by iodonium salts studied is similar. Most of the iodonium salts exhibit no large differences regarding the reactivity in initiation of TMPTA polymerization. However, an introduction of a nitro group in the para position of the phenyl ring of the co-initiator results in a significant increase in the rate of polymerization and degree of monomer conversion. The dye-sensitized photoreaction mechanism of the SQ/I system was also confirmed.