Reversible and irreversible thermochromic phase transitions in single crystals of polydiacetylenes substituted with alkyl‐urethanes
Reversible and irreversible thermochromic phase transitions in single crystals of polydiacetylenes substituted with alkyl‐urethanes
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烷基氨基甲酸酯取代的聚二乙炔单晶中的可逆和不可逆热致变色相变
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
A. Kobayashi
中科院分区：
文献类型：
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作者：
S. Koshihara;Y. Tokura;K. Takeda;T. Koda;A. Kobayashi
研究了一类新的烷基氨基甲酸酯侧基取代的聚二乙炔（PDA）[−（CH 2）4 OCONH（CH 2）n− 1CH 3：n =1−10]在两个光谱上不同的相（A和B相）之间的可逆转变。光谱测量以及X射线和量热研究揭示了一系列n=1-10的PDA中的一级相变，其与宽度从0到60 K的n依赖性热滞后相关。已经发现，一旦侧基中的氢键链被加热超过聚合物熔融温度而中断，则所有这些PDA中的热致变色变化变得不可逆。
Reversible transitions between the two spectroscopically distinct phases (A and B phases) have been investigated for a new family of polydiacetylenes (PDAs) substituted with side groups of alkyl‐urethane [−(CH2)4OCONH(CH2)n−1CH3:n =1−10]. Measurements of optical spectra as well as x‐ray and calorimetric studies have revealed the first‐order‐like phase transitions in a series of PDAs with n=1–10 which are associated with an n‐dependent thermal hysteresis ranging from 0 to 60 K in width. It has been found that the thermochromic changes become irreversible in all these PDAs once the hydrogen bond chains in the side groups are interrupted by heating beyond the polymer melting temperature.