Synthesis and Structure Properties of Gradient-Modulus Star Copolymers

梯度模量星形共聚物的合成及结构性能

基本信息

批准号：
09650973
负责人：
ISHIZU Koji
金额：
$ 1.86万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650973/
关键词：
Gradient-modulus structure Star Copolymers Superlattice structure スター芝重合体超格子

项目摘要

The aim of this project is to study the novel synthesis and structural ordering of gradient-modulus star copolymers. The results obtained are as follows.1. Gradient-modulus star copolymers were prepared by crosslinking poly[isoprene(I)-block-I/styrene(S)-block-S] tapered block monoanions with divinylbenzene(DVB) in benzene. The dilute-solution properties of these stars were characterized by static and dynamic light scattering (SLS and DLS). The ratio of radius of gyration over the Stokes radius (R_G/R_H) in benzene decreased gradually and approached unity as the arm number became large. Even gradient-modulus stars with multiarms behave not as near hard spheres but as soft spheres which were penetrable near the edge in a good solvent. It was found from the results of DLS that gradient-modulus stars formed unimolecular micelles even in selective solvent.2. Structural orderings of stars were investigated through the small-angle X-ray scattering in benzene and through the transmission electron microscopy (TEM) measurements. All of the star samples formed a lattice with a body-centered-cubic (BCC) structure near the overlap threshold (C'). In the star specimens with arm number n<67, this structure changed to the lamellae in the bulk film, in the star specimen with n=289, it showed an interesting tendency for the spherical structure to be maintained with the dimension of the unimolecular micelle even in the bulk film.3. Gradient-modulus stars formed a lattice with BCC structure near the C'. After these stars formed a cubic lattice in methyl methacrylate (MMA) monomer, the polymeric superstructures were constructed by locking permanently ordered lattice in a solid matrix by means of free-radical polymerization of MMA monomer. This technique is one of the best methods fir creating nanoscopic polymeric superstructures.

该项目的目的是研究梯度模量星形共聚物的新颖合成和结构排序。得到的结果如下： 1．通过聚[异戊二烯(I)-嵌段-I/苯乙烯(S)-嵌段-S]递变嵌段单阴离子与二乙烯基苯(DVB)在苯中交联制备了梯度模量星形共聚物。这些恒星的稀溶液特性通过静态和动态光散射（SLS 和 DLS）来表征。随着臂数的增加，苯中的回转半径与斯托克斯半径之比（R_G/R_H）逐渐减小并接近于1。即使是具有多臂的梯度模星，其行为也不像硬球体附近，而是软球体，在良好溶剂中可以在边缘附近渗透。 DLS结果发现，即使在选择性溶剂中，梯度模星星也能形成单分子胶束。 2．通过苯中的小角 X 射线散射和透射电子显微镜 (TEM) 测量来研究恒星的结构排序。所有恒星样本在重叠阈值 (C') 附近形成具有体心立方 (BCC) 结构的晶格。在臂数n<67的星形样品中，这种结构转变为块体膜中的片层，在n=289的星形样品中，表现出随着单分子胶束的尺寸而保持球形结构的有趣趋势即使在散装薄膜中也是如此。3。梯度模量星在C'附近形成了具有BCC结构的晶格。这些星形在甲基丙烯酸甲酯（MMA）单体中形成立方晶格后，通过MMA单体的自由基聚合将永久有序的晶格锁定在固体基质中，从而构建了聚合物超结构。该技术是创建纳米级聚合物超结构的最佳方法之一。