Azo-aromatic functionalized polyethylene by nitroxide radical coupling (NRC) reaction: Preparation and photo-physical properties
作者:Francesca Cicogna、Ilaria Domenichelli、Serena Coiai、Fabio Bellina、Marco Lessi、Roberto Spiniello、Elisa Passaglia
DOI:10.1016/j.polymer.2015.11.018
日期:2016.1
behavior of the free and grafted RO-TEMPO molecules was carried out by UV-Vis spectroscopy irradiating the free RO-TEMPO solutions and the functionalized polymer films at 366 and 254 nm. Results evidenced the transfer of the photo-physical properties of the chromophores to the polymer matrix. Interestingly, some different isomerization abilities and kinetics between the free and grafted RO-TEMPO moieties
4-(苯基偶氮)-苯甲酰基-2,2,6,6-四甲基哌啶-1-氧基(AzO-TEMPO)或4-(2-噻吩基偶氮)-苯甲酰基-2之间的氮氧自由基偶联(NRC)反应1,2,6,6-四甲基哌啶-1-氧基(ThiO-TEMPO)和聚乙烯基自由基可以制备带有共价接枝的偶氮-芳族发色团的“功能性”聚烯烃。通过UV-Vis光谱对游离的RO-TEMPO溶液和官能化的聚合物膜在366和254nm处进行辐照,比较了游离的和接枝的RO-TEMPO分子的光物理行为。结果证明了生色团的光物理性质向聚合物基质的转移。有趣的是,游离和接枝的RO-TEMPO部分之间存在一些不同的异构化能力和动力学,观察到取决于与重氮基团键合的芳族基团的性质以及聚合物基体的结构。实际上,当发色团接枝到聚合物上时,异构化导致的光异构化程度和异构化速率不如溶液有效,这表明半结晶基质的作用特别强,特别是在刚性较大的情况下。高密度聚乙烯。最后,在光