Enthalpy relaxation and fragility in polychlorinated biphenyls

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• 作者：C M Roland and R Casalini
• 关键词：chlorinated biphenyl ; fragility ; glass transition ; PCB ; TMDSC
• 刊名：Journal of Thermal Analysis and Calorimetry
• 出版年：2006
• 出版时间：January 2006
• 年：2006
• 卷：83
• 期：1
• 页码：87-90
• 全文大小：217 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Sciences
  Polymer Sciences
  Physical Chemistry
  Inorganic Chemistry
  Measurement Science and Instrumentation
  
• 出版者：Akad茅miai Kiad贸, co-published with Springer Science+Business Media B.V., Formerly Kluwer Academic
• ISSN：1572-8943

文摘

We employ temperature modulated DSC (TMDSC) to determine the dependence of the fictive temperature on cooling rate for a series of polychlorinated biphenyls (PCB). From the slopes of semi-logarithmic plots of cooling rate vs. fictive temperature, the latter normalized by the fictive temperature for an arbitrary cooling rate, we determine the enthalpic fragilities. Despite significant differences in glass transition temperature and chemical structure (specifically chlorine content), the PCB have the same fragility. The value of the fragility determined using TMDSC is consistent with the fragility previously determined using dielectric relaxation spectroscopy.