聚丙烯
战术性
材料科学
玻璃化转变
热容
热力学
中间相
相变
大气温度范围
Crystal(编程语言)
相(物质)
副晶态
高分子化学
聚合物
分析化学(期刊)
复合材料
结晶学
化学
有机化学
液晶
物理
光电子学
计算机科学
聚合
程序设计语言
作者
Janusz Grȩbowicz,Suk-Fai Lau,Bernhard Wunderlich
出处
期刊:Journal of Polymer Science: Polymer Symposia
[Wiley]
日期:1984-01-01
卷期号:71 (1): 19-37
被引量:173
标识
DOI:10.1002/polc.5070710106
摘要
Abstract The thermodynamic properties of isotactic polypropylene in the fully crystalline, glassy, and molten state are established from 0 to 500 K based on data bank heat capacities and the vibrational frequency spectrum. The seven skeletal vibrations are described by θ 3 and θ 1 of 91 and 714 K for crystalline polypropylene. For the calculation of C p − C v , a Lindemann A 0 value of 1.5 × 10 −3 K mol/J was found. Calculated and experimental heat capacity data show agreement within an average error of −0.3 ± 1.6%. Glassy polypropylene was similarly treated up to the glass transition temperature at 260 K (θ 3 = 78 K, θ 1 = 633 K, average heat capacity error −0.6 ± 2.8%). The residual 0 K entropy of glassy polypropylene is 1.9 J/K mol. Partially crystalline polypropylene is shown through high‐sensitivity DSC measurements to have a glass transition range from 260 to 380 K. Similarly, high‐sensitivity DSC has been used to characterize the condis phase of polypropylene (conformationally disordered polypropylene) which was prior called “smectic mesophase” or “paracrystalline.” Its heat of transformation to the stable crystal phase is 600 J/mol.
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