Abstract

The effect of fillers, polysulfone and polyetherimide, on the mechanism and kinetics of the thermo-oxidative degradation of a composition based on an epoxy oligomer cured with 4,4'-diaminodiphenyl sulfone which proceeds under heating in the nonisothermal regime is studied. A relationship is revealed between the structure of the composition and the mechanism and kinetic parameters of the process, on one hand, and the chemical nature of the filler, on the other hand. Mechanistic and kinetic features of the nonisothermal degradation of the epoxyamine composition are ascertained by the thermoanalytical method using differential scanning calorimetry. The kinetic parameters of the process are assessed by an analysis of thermokinetic curves in terms of thermokinetic models and the examination of oxidation products. Depending on the filler nature and composition structure, reactions involving bonds of interjunction chains and junctions of the network of the epoxy polymer as well as radical reactions of the active centers of the filler occur in the polymer during thermal oxidation. An increase in the network density and the localization of the filler determine the contribution of the diffusion factor, decrease the rate of thermo-oxidative degradation of interjunction chains, and increase the rate of breakdown of network junctions.

中文翻译：

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含热塑性填料的环氧低聚物基组合物的热氧化降解特性

摘要

研究了填料、聚砜和聚醚酰亚胺对基于用 4,4'-二氨基二苯砜固化的环氧低聚物的组合物的热氧化降解机理和动力学的影响，该组合物在非等温状态下加热进行。一方面揭示了组合物的结构与过程的机制和动力学参数之间的关系，另一方面揭示了填料的化学性质之间的关系。环氧胺组合物的非等温降解的机械和动力学特征通过使用差示扫描量热法的热分析方法确定。该过程的动力学参数通过根据热动力学模型分析热动力学曲线和检查氧化产物来评估。根据填料的性质和组成结构，在热氧化过程中，聚合物中会发生涉及环氧聚合物网络的连接链和连接点的键以及填料活性中心的自由基反应的反应。网络密度的增加和填料的定位决定了扩散因子的贡献，降低了连接链的热氧化降解率，并增加了网络连接的破坏率。