Structure and Viscoelastic Properties of Diblock Copolymers in Disordered State

无序状态二嵌段共聚物的结构和粘弹性能

基本信息

批准号：
09650994
负责人：
TAKAHASHI Yoshiaki
金额：
$ 1.86万
依托单位：
Nagoya University
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

项目摘要

We have studied structure and viscoelastic properties of poly(styrene-b-2-vinyl-pyridine)s and their deutrated counterparts in the disordered state near the order-disorder transition (ODT) both in bulk and in a common good solvent. This specimen is suitable for such study since both components have almost the same physical properties but still segregate at certain conditions. The results we have achieved are listed as follows.(1)We determined ODT for the block copolymer samples in wide ranges of molecular weight (10k to million) and concentration (10% up to bulk) by rheometry and small angle neutron scattering (SANS) measurements. The data in semidilute region could be explained by the theory which account for fluctuation effect. However, the transition between semidilute and concentrated regions was not clear.(2)We found that the elastic parameters obtained by dynamic mechanical analysis are a few times larger than those of components but the elastic parameters measured by steady shear flow become almost the same as those of components. The difference cannot be explained by rheological behavior alone. There are two possibilities ; one is flow-induced ordering and another is suppression of fluctuation by steady shear flow.(3)To clarify above behavior, we performed flow-SANS measurements at the corresponding condition and found that there is no flow-induced microdomain structure so that we concluded the above viscoelastic behavior can be explained by fluctuation effect and its suppression under steady shear flow.

我们研究了聚（苯乙烯-B-2-乙烯基 - 吡啶）S及其在散装和常见的良好溶剂中的秩序disordordertrion（ODT）附近的无序状态的剥离状态的结构和粘弹性。该标本适用于此类研究，因为两个组件的物理特性几乎相同，但仍在某些条件下隔离。（1）我们确定了分子量较大的块共聚物样品（10k至百万到百万）的ODT（100 k到百万），并通过风湿和小角度中子散射（SANS）（SANS）（SANS）（SANS）（sans sans）确定了块共聚物样品的ODT ）测量。半硅区域中的数据可以用该理论来解释，该理论说明了波动效应。然而，半足球区域和浓缩区之间的过渡。（2）我们发现，通过动态机械分析获得的弹性参数比组件的弹性参数大几倍，但是通过稳定剪切流量测量的弹性参数几乎与组件的那些。差异不能仅通过流变行为来解释。有两种可能性；一种是流动诱导的排序，另一个是通过稳定的剪切流抑制波动。（3）为了阐明上述行为，我们在相应的条件下进行了流-SANS测量，发现没有流动诱导的微域结构，以便我们得出结论上述粘弹性行为可以通过波动效应及其在稳定的剪切流下的抑制来解释。