Structural Change in the Topochemical Solid-State Polymerization Process of Diethylcis,cis-Muconate Crystal. 1. Investigation of Polymerization Process by Means of X-ray Diffraction, Infrared/Raman Spectra, and DSC
Structural Change in the Topochemical Solid-State Polymerization Process of Diethylcis,cis-Muconate Crystal. 1. Investigation of Polymerization Process by Means of X-ray Diffraction, Infrared/Raman Spectra, and DSC
复制标题
二乙基顺,顺-粘康酸酯晶体的拓扑化学固态聚合过程中的结构变化。
DOI：
10.1021/ma981327b
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发表时间：
1999
期刊：
影响因子：
5.5
通讯作者：
S. Aoki
中科院分区：
文献类型：
--
作者：
K. Tashiro;T. Kamae;Masamichi Kobayashi;A. Matsumoto;Katsutaka Yokoi;S. Aoki
本文用X射线衍射、红外光谱、拉曼光谱和DSC研究了顺，顺粘康酸二乙酯晶体在光引发固相聚合过程中的结构变化。红外和拉曼光谱的变化，在此聚合反应可以解释的基础上，一个简单的双组分系统组成的单体和聚合物分子。这种明显的观察可能源于振动光谱对局部结构的高灵敏度。时间分辨X射线衍射结果表明，在聚合过程中，聚合物的晶格间距是连续变化的，这表明在聚合过程中，由于不同长度或体积的单体和聚合物的化学物种的共存，对晶格的应变发生了变化。但这种应变相当小，并且在聚合反应期间或多或少可以保持晶格。还发现，在低于-40 °C的低温下不发生聚合，在该低温下发生相转变并且单体分子的堆积结构发生改变，如由X射线衍射图案的大的变化所指示的。反应性和晶体结构之间的这种良好相关性表明聚合反应敏感地受单体分子的堆积结构控制;即，该反应正是晶格控制聚合。
Structural change occurring in the light-induced solid-state polymerization of diethyl cis,-cis-muconate crystal has been investigated by means of the X-ray diffraction, infrared and Raman spectra, and DSC. The infrared and Raman spectral changes during this polymerization reaction could be interpreted on the basis of a simple two-component system consisting of monomer and polymer molecules. This apparent observation may originate from the high sensitivity of the vibrational spectra to the local structure. The time-resolved X-ray diffraction measurement, however, showed that the lattice spacings changed continuously in the process of polymerization, indicating that the strain to the crystal lattice, due to the coexistence of the different chemical species of monomer and polymer with various lengths or volumes, changed in this reaction. But this strain was quite small, and the crystal lattice could be maintained more or less during the polymerization reaction. It was also found that the polymerization did not occur at a low temperature below -40 °C, where the phase transition occurred and the packing structure of monomer molecules changed, as indicated by the large change in the X-ray diffraction pattern. This good correlation between the reactivity and the crystal structure indicates that the polymerization reaction is governed sensitively by the packing structure of monomer molecules; i.e., this reaction is just the lattice-controlled polymerization.