添加六次甲基四胺对芘热缩聚产物的影响

Effects of hexamethylenetetramine on the thermal polycondensation of pyrene

为了研究六次甲基四胺对芘热缩聚的影响,分别以芘或芘与六次甲基四胺的混合物为原料在480℃进行热缩聚反应,并利用MALDI-TOF-MS、13C-NMR、FT-IR、元素分析和热台显微镜对热缩聚产物的组分、结构进行分析表征。测试结果表明,添加六次甲基四胺后,芘单体能够完全转化为低聚体,热缩聚产物中的碳元素含量和氯仿不溶物含量升高。此外,元素分析结果显示六次甲基四胺在芘热缩聚过程中(400℃)能够与芘相结合,随着反应温度的提高(480℃),大部分六次甲基四胺从反应体系中排出。这些研究结果说明六次甲基四胺对于芘的热缩聚反应具有明显的催化作用。

To study the effects of hexamethylenetetramine on the thermal polyeondensation of pyrene, pyrene or the mixture of pyrene andhexamethylenetetramine was heated at 480 ℃ for 3 hour under N2 atmosphere. The composition and molecular structures of the products were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF）, 13C nuclear magnetic resonance （NMR）, elemental analyzer,FT-IR spectroscopy and polarizing microscope with hot stage . The results show that, with the addition of hexamethylenetetramine, pyrene monomer can be fully converted to oligomer and the carbon element ratio of resulted oligomer increases. Furthermore, the content of chloroform insoluble component in resulted oligomer also increased by adding hexamethylenetetramine. The results of element analysis show that hexamethylenetetramine can react with pyrene during polycondensation of pyrene at 400℃, and then they escape from reaction system with the reaction temperature increasing to 480℃. The results suggest that hexamethylenetetramine has obvious catalysis on the thermal polymerization of pyrene.