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首页> 外文期刊>Journal of Applied Polymer Science >High-resolution thermogravimetry of polyethersulfone chips in four atmospheres
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High-resolution thermogravimetry of polyethersulfone chips in four atmospheres

机译：四种气氛下聚醚砜芯片的高分辨率热重分析

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Thermal degradation and kinetics of polyethersulfone (PES) chips were studied in air, nitrogen, helium, and argon from room temperature to 790degreesC by high-resolution thermogravimetry (TG) at a variable heating rate in response to changes in the sample's degradation rate. In the four atmospheres, a two-step degradation process in air, argon, and helium or a three-step degradation process in nitrogen of the PES were found in this investigation. In particular, the three-step degradation process in nitrogen of the PES revealed by the high-resolution TG was hardly ever observed by a traditional TG. The initial thermal degradation temperature of the PES increases with the testing atmosphere in the following order: air < argon < helium < nitrogen but the activation energy of the first major degradation of PES increases in a different order: argon < nitrogen < helium < air. The degradation temperature, the temperature at the maximum weight-loss rate, the maximum weight-loss rate [(dalpha/dT)(m1) and (dalpha/dT)(m2)], char yield at 790degreesC, and activation energy of the first major degradation process obtained by the high-resolution TG were compared with those by traditional TG. The PES exhibits the largest (dalpha/dT)(m1) and the greatest char yield at 790degreesC in helium but the largest (dalpha/dT)(m2) and smallest char yield in air. A significant dependency of the thermal decomposition of the polymers on the physicochemical properties (density, thermal conductivity, and oxidative ability) of the testing atmospheres is elaborated for the first time. (C) 2003 Wiley Periodicals, Inc. [References: 30]
机译：响应于样品降解速率的变化，通过可变热速率的高分辨率热重分析法（TG）在室温，790℃的空气，氮气，氦气和氩气中研究了聚醚砜（PES）芯片的热降解和动力学。在此研究中，发现在四种大气中，空气，氩气和氦气中的两步降解过程或氮中的三步降解过程。尤其是，传统TG几乎没有观察到高分辨率TG揭示的PES氮气中的三步降解过程。 PES的初始热降解温度随​​测试气氛按以下顺序增加：空气<氩<氦<氮，但PES的第一次主要降解的活化能以不同的顺序增加：氩<氮<氦<空气。降解温度，最大失重率下的温度，最大失重率[（dalpha / dT）（m1）和（dalpha / dT）（m2）]，790℃下的焦炭收率和活化能将高分辨率TG获得的第一个主要降解过程与传统TG进行了比较。 PES在790摄氏度的氦气中表现出最大的（dalpha / dT）（m1）和最大的焦炭产量，但在空气中表现出最大的（dalpha / dT）（m2）和最小的焦炭产量。首次详细阐述了聚合物热分解对测试气氛的物理化学性质（密度，导热率和氧化能力）的重要依赖性。 （C）2003 Wiley Periodicals，Inc. [参考：30]

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