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大分子溶致凝聚过程中体系熵值的变化
  • ISSN号:1003-3726
  • 期刊名称:高分子通报
  • 时间:0
  • 页码:1-4
  • 分类:O631.13[理学—高分子化学;理学—化学]
  • 作者机构:[1]青岛科技大学高分子科学与工程学院,青岛266042
  • 相关基金:国家自然科学基金资助项目(50973050);
  • 相关项目:聚合物熔体高速挤出异常流变性的“指纹”识别,扰动源分析及有效对策
作者: 吴其晔|
中文摘要:

讨论了大分子溶致凝聚过程中体系熵变的特点和影响。在分子链无规凝聚形成无定形聚合物时,正是熵增的贡献使体系自由能下降,无规凝聚过程得以进行。在有规凝聚形成结晶聚合物时,熵变对结晶过程产生复杂影响。由于熵变和内能变化相互竞争,使溶致结晶时最优生成的晶体结构为松散折叠链片晶;而从熔体结晶时则得到晶相和非晶相(无定形相)两相并存的复杂结构。区分了两类不同性质的熵变:阶跃性熵变导致熵致相变发生;渐变性熵变使体系力学性质变化或发生力学状态转变。

英文摘要:

In this work the features and influences of entropy in the lytropic condensation of macromolecules were discussed. In an irregular condensation, in that the amorphous polymers were generated, just the entropy increase causes a decrease of Helmholtz's free energy, and so that the condensation process can go on. In a regular condensation, in that the crystalline polymers were generated, the change of entropy induces very complex effects for polymer crystallization. Due to the competition between entropy and internal energy, a folded chain lamellae with loose structure was prior generated in the lytropic crystal process ~ and a two phases structure with crystal and amorphous region was generated in the crystal process from polymer melts. Two different changers ways of entropy were distinguished~ a jump change of entropy can induce a thermodynamic phase transition-entropy induced phase transition, but a gradual change of entropy can change only the mechanical property or initiate a mechanical state transition of polymers.

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期刊信息
  • 《高分子通报》
  • 中国科技核心期刊
  • 主管单位:中国科学技术协会
  • 主办单位:中国化学会 中国科学院化学研究所
  • 主编:黄志镗
  • 地址:北京中关村北一街二号(北京2709信箱)
  • 邮编:100190
  • 邮箱:gfztb@iccas.ac.cn
  • 电话:010-62588926
  • 国际标准刊号:ISSN:1003-3726
  • 国内统一刊号:ISSN:11-2051/O6
  • 邮发代号:80-294
  • 获奖情况:
  • 国内外数据库收录:
  • 被引量:12665