基于2,2,6,6-四甲基-1-哌啶氧自由基捕捉技术的9,9'-二芴-9,9'-二醇引发聚合机理研究

Study of the initiation mechanism of 9,9'-bifluorene-9,9'-diol by radical trapping technology using (2,2,6,6-tetramethylpiperidin-1-yl) oxyl

采用2,2,6,6-四甲基-1-哌啶氧自由基(TEMPO)捕捉9,9'-二芴-9,9'-二醇(BFDOL)在分解和引发过程中产生的自由基。利用液相色谱-质谱联用技术、质子核磁共振技术和碳同位素核磁共振技术对捕捉产物分离和结构解析,并表征了混合产物的组成;利用折光示差-紫外吸收双检测液相色谱技术追踪聚合反应动力学。实验结果证实了BFDOL氢转移的引发途径,并提出了β-断裂机理,同时对体系中夺氢及其他引发机理的可能性进行了讨论。

The dissociation and initiation process of 9, 9＇-bifluorene-9,9＇-diol （BFDOL） were studied by a radical trapping technique using （2,2,6,6-tetramethylpiperidin-l-yl） oxyl （TEMPO） in the bulk and in three solvents-- anisole, toluene and tetrahydrofuran. The chemical structures of the trapped products were analyzed by liquid chro- matography/mass spectrometry, I H-NMR and ,13C-NMR spectroscopy, and the kinetics of polymerization were stud- ied by gel permeation chromatography （ GPC ） with a differential refractive index - ultraviolet double detector. Based on the experiments, we propose that the initiation pathway of BFDOL involves a β-scission mechanism, al- though abstraction and other possible pathways are also possible.