A Study on the mechanism of ordered-structure formation in triblock copolymers consisting of crystalline/non-crystalline/liquid-crystalline blocks.

这项研究旨在阐明由液晶、结晶和非结晶聚合物嵌段组成的共聚物形成的有序结构。采用具有分子内氢键的棒状结构的聚谷氨酸苄酯(PBLG)作为液晶聚合物嵌段，选择聚环氧丙烷(PPO)和聚环氧乙烷(PEO)分别作为非晶态和晶态聚合物嵌段。结果表明，相态、温度、环境和聚合物嵌段的分凝顺序对形成有序结构有影响。(1)用光散射法研究了PEO-PBLG在溶液中形成的缔合物的有序结构。在含有少量水的二氯乙烷中，PEO-PBLG与聚乙二醇嵌段核形成缔合。另一方面，嵌段共聚物在二氯乙烷和乙醇的混合溶剂中形成由PBLG核组成的棒状缔合物。在PBLG组成较高的共聚物中，缔合尺寸随着温度的降低而显著增大，而在PBLG组成较低的共聚物中，缔合尺寸逐渐变化。(2)用小角X射线散射法研究了固体PBLG-g-(PPO-b-PEO)的有序结构，并与PBLG-g-PEO的有序结构进行了比较。在BLG-g-(PPO-b-PEO)中观察到了约200a的间距，而在PBLG-g-PEO中没有观察到。这表明，非晶链的存在影响了形态结构，这取决于PEO链是熔融的还是结晶的。

This study aims to elucidate the ordered structures formed by copolymers consisting of liquid-crystalline, crystalline, and non-crystalline polymer blocks. Poly(gamma-benzyl L-glutamate)(PBLG), which takes a rod-like structure with intramolecular hydrogen bonds, was used as the liquid-crystalline polymer block, and poly(propyreneoxide)(PPO) and poly(rthyleneoxide)(PEO) were chosen as non-crystalline and crystalline polymer blocks, respectively. The following results have been found, which demonstrate the effects of phase states, temperature, surroundings, and the order of segregation of polymer blocks on the ordered structure formed. (1) The ordered structure of associates of PEO-PBLG formed in solution has been investigated by light scattering. The PEO-PBLG forms associates with cores of PEG blocks in dichloroethane containing a small amount of water. This associate is suggested to take a novel structure of a rod-like core PEG with grafted rod-like PBLG.On the other hand, the block copolymer in the mixed solvent of dichloroethane and ethanol forms rod-like associates consisting of PBLG cores. In the copolymer with a higher PBLG composition, the associate size dramatically increases with decreasing temperature, while in the copolymer of a lower PBLG composition, the size changes gradually. (2) The ordered structure of solid PBLG-g-(PPO-b-PEO) has been investigated by small angle x-ray scattering, and compared with that of PBLG-g-PEO.In BLG-g-(PPO-b-PEO), the spacing of about 200A is observed, while it is not in PBLG-g-PEO.This demonstrates that the morphological structure is affected by the presence of non-crystalline chains and depends on whether PEO chains are in melt or crystallized.