Abstract

Organometallic dendrimers are one of the most attractive macromolecules owing to their unique properties that derived from the combination of the metallic moieties and the remarkable architecture of the dendrimers. A new family of organoiron dendrimers has been synthesized using divergent methodology. To gain insight into the stability of these dendrimers, we investigated their thermal property using nonisothermal thermogravimetry analysis (TGA), which reveal the kinetic triplets, the pre-exponential factor, the effective activation energy and the reaction model involved in their thermal degradation. The results were obtained at heating rates of 10, 15 and 20 °C min⁻¹. Four nonisothermal methods, the Friedman, the Ozawa and Flynn and Wall, the Kissinger–Akahira–Sunose and the Minimizing were used to investigate the variation of the effective activation energy with the extent of crystallization and, hence, with temperature. In addition, the activation energy was calculated from isothermal data. The degradation mechanism follows the Avrami–Erofeev mechanism for solid-state reaction models.

Graphic Abstract

中文翻译：

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一个新的有机金属树枝状大分子的热降解行为

摘要

有机金属树枝状大分子由于其独特的性质而成为最吸引人的大分子之一，这些性质源于金属部分的结合以及树枝状大分子的卓越结构。使用发散方法合成了新的有机铁树枝状大分子家族。为了深入了解这些树枝状聚合物的稳定性，我们使用非等温热重分析（TGA）研究了它们的热性能，该分析揭示了动力学三联体，前指数因子，有效活化能以及涉及其热降解的反应模型。在10、15和20°C min ^-1的加热速率下获得结果。弗里德曼（Friedman），小泽（Ozawa）和弗林（Flynn）和沃尔（Kissinger–Akahira–Sunose）和极小化（Minimizing）这四种非等温方法用于研究有效活化能随结晶程度以及温度的变化。另外，根据等温数据计算活化能。对于固态反应模型，降解机制遵循Avrami-Erofeev机制。

图形摘要