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铁虫 (正式写手)

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虫号: 4532612
注册: 2016-03-23
专业: 高分子合成化学

[交流] 采用DSC和流变对琥珀的热和机械性能进行表征已有1人参与

Amber is a fossil resin well known for its natural beauty and special characteristics. In this note, we describe the use of a DSC Q20 and an ARES rheometer (TA Instruments, New Castle, DE) to characterize amber’s thermal properties and mechanical behavior. Firstly, amber samples having different ages and from different locations were tested for thermal properties using the DSC Q20. The fictive temperatures and the glass transition temperatures for stable ambers were obtained from the first and second heating loop. The DSC results show that most of the amber samples are unstable, hence fictive temperature could not be obtained. We also find that there is no age dependence for the glass transition temperature for different amber samples. A piece of stable Dominican amber (20 million years old) with a glass transition temperature of 136.2 °C was found in the DSC tests, and the ARES rheometer was used in the torsion rectangular mode to obtain the stress relaxation behavior from room temperature to 160 °C. Time-temperature superposition (TTS) was applied to the stress relaxation responses of amber at different temperatures, and the master curve was obtained from TTS.

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