A Study for the Mesomorphic State of Polyorganophosphazene in Terms of Time-sharing X-ray Diffraction

可结晶的聚有机磷腈（POP）具有所谓的T（1）转变，在该转变处聚合物从其3-D有序结晶状态变为3-D有序介晶结构（例如，delta阶段）。该过渡通常被称为位于玻璃化转变温度和真正的熔点之间的POP.In这项研究中，结晶过程中的结构研究与两种类型的聚磷腈的δ相已进行了分时X-射线衍射方法，并与这些POP检查的热性能的研究结果进行了比较。结果表明：（1）聚[双（4-乙基苯氧基）磷腈]（PB（4 E）PP）薄膜在140 ℃加热后迅速冷却至75 ℃等温时，聚合物仍保持介晶状态，没有结晶。通过PSPC的X射线实验证实了这种中间态的冻结。(2)通过300 K/mm的快速冷却速率获得的PB（4 E）PP膜的热谱图没有显示任何放热行为，这与上述观察到的结构特征一致。(3)用低温扫描电镜研究了PB（4 E）PP的冷冻形态特征。(4)我们以类似的方式使用分时X射线衍射和DSC研究了聚（双（3，4-二甲基苯氧基）-磷腈]（PB（dM）PP）的δ相的结晶行为，并通过将样品快速冷却至室温成功地冻结了其介观状态。当样品温度再次升高至70 ℃时，在具有晶体改性的公司中发生结晶。这些研究结果表明，链折叠可能没有发挥重要的作用，在PB（dM）PP的结晶过程中。更多的X射线衍射工作同步辐射实验，特别是，将需要遵循的整个过程中的结晶的聚合物。今后将继续沿着这条路线开展工作。

Crystallizable polyorganophosphazenes (POP) have so-called T(1) transitions at which the polymers change from their 3-D ordered crystalline state to the 3-D ordered mesomorphic structure ( e.g., the delta phase ). The transition is generally known to locate between the glass transition temperature and the true melting point of POP.In this research, structural studies for crystallization processes from the delta phases associated with two types of polyphosphazenes have been carried out by a time-sharing x-ray diffraction method, and the findings were compared with the thermal properties of those POP examined. The results obtained are summarized as follows :(1) When the poly[bis(4-ethylphenoxy)phosphazene] (PB(4E)PP) films heated at 140ﾟC were cooled down rapidly to an isothermal temperature of 75ﾟC, the mesomorphic states of the polymer remained without crystallization. This freezing of the meso state was confirmed by the x-ray experiments with PSPC.(2) The thermogram for the PB(4E)PP film obtained by a rapid cooling rate of 300 K/mm did not indicate any exothermic behavior, as agreed with the structural features above observed.(3) Morphological features of freezed PB(4E)PP were also investigated by use of a cryo SEM.(4) We examined the crystallization behavior of the delta phase of poly(bis(3,4-dimethylphenoxy)- phosphazene] (PB(dM)PP) in a similar manner using time-sharing x-ray diffraction and DSC, and succeeded in freezing its meso state by cooling the sample rapidly down to room temperature. When the sample temperature was raised again to 70ﾟC, crystallization occurred in a company with crystal modification. These findings indicate chain foldings probably did not play an important role in the crystallization process in PB(dM)PP.More x-ray diffraction works by synchrotron experiments, in paticular, will be required to follow the whole process of crystallization of both the polymers. The works along this line will be continued in future.