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首页> 外文期刊>Journal of Spacecraft and Rockets >Thermal Contributions to the Degradation of Ground Laboratory and Space-Irradiated Teflon~(~R)
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Thermal Contributions to the Degradation of Ground Laboratory and Space-Irradiated Teflon~(~R)

机译：热对地面实验室和空间辐照聚四氟乙烯〜（〜R）降解的贡献

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The aluminized Teflon~(~R) fluorinated ethylene propylene outermost layer of the multilayer insulation blankets on the Hubble Space Telescope has become embrittled, resulting in severe on-orbit cracking. During the second servicing mission, a piece of aluminized fluorinated ethylene propylene was retrieved. This cracked piece of insulation had curled on-orbit, exposing the backsurface aluminum to space. This extremely embrittled piece reached 200℃ on orbit, 150℃ higher than the nominal temperature extreme. Therefore, experiments have been conducted to determine the effect of heating on the degradation of fluorinated ethylene propylene that has been irradiated in a ground laboratory facility or in space on the Hubble Space Telescope. Samples of pristine, x-ray irradiated and Hubble Space Telescope retrieved fluorinated ethylene propylene were heat treated from 50 to 200℃ at 25℃ intervals in a high vacuum facility and tensile tested. Density measurements were also obtained. Results indicate that heating does not embrittle nonirradiated Teflon. However, there is a significant dependence of the embrit-tlement of irradiated Teflon on heating temperature, with near complete loss of elongation at 100℃ and higher. Rate of degradation changes, which were consistent with the glass transition temperature for fluorinated ethylene propylene, were present in the data. The results support chain scission as the primary mechanism of degradation of fluorinated ethylene propylene on the Hubble Space Telescope and indicate the significance of the on-orbit temperature of fluorinated ethylene propylene with respect to its degradation in the space environment.
机译：哈勃太空望远镜上多层绝缘毯的镀铝的特氟隆氟化乙烯丙烯最外层已经变脆，导致严重的在轨裂纹。在第二次维修任务中，回收了一块铝化的氟化乙烯丙烯。破裂的绝缘材料在轨道上弯曲，使背面铝板暴露在太空中。这个极易碎的碎片在轨道上达到200℃，比标称极端温度高150℃。因此，已经进行了实验以确定加热对已经在地面实验室设施或哈勃太空望远镜上的空间中辐射的氟化乙烯丙烯降解的影响。原始样品，X射线辐照和哈勃太空望远镜回收的氟化乙烯丙烯样品在高真空设备中以50℃至200℃的间隔每25℃进行热处理，并进行了拉伸测试。还获得了密度测量值。结果表明，加热不会使未辐照的聚四氟乙烯变脆。但是，辐照的聚四氟乙烯的脆度与加热温度有很大的相关性，在100℃及更高的温度下几乎完全丧失了伸长率。数据中显示了与氟化乙烯丙烯的玻璃化转变温度一致的降解速率。结果支持断链作为哈勃太空望远镜上氟化乙烯丙烯降解的主要机理，并表明氟化乙烯丙烯在轨温度对其在太空环境中降解的重要性。

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