| Research Abstract |
Polystyrenes having controlled molecular weights, nearly monodisperse molecular weight distributions, and among group at the chain terminal were prepared by anionic living polymerization.
Similarly, polyethylene oxides with well defined chain structure and the terminal carboxy group were obtained. A mixture of the polystyrene with amino terminal and the polyethlene oxide with carboxy end group was cast into a thin film, which was found to have microphase separated lamellar structure like a block copolymer through the strong interaction between amino and carboxy groups by using transmission electron micrography(TEM) and small angle X-ray scattering(SAXS). The periodicities of the structure measured by TEM and SAXS agreed reasonably with the one estimated from the molecular weights of the telechelic polymers. Furthermore, the effects of the mixing molar ratio of the polymers, casting solvents, and the molecular weights of the polymers on the microphase separated structure were investigated. Regardless of the molar ratio of the telechelic polymers, the lame1lar structure was observed in the range of 1:2 to 2:1. Benzene, dioxane, and tetrahydrofurane gave similar periodicities, whereas small domain size was observed when cast from chloroform. The telechelic polymers of lower molecular weights form more regular structure although the telechelic polystyrene with larger molecular weight( 3 x 10^4 ) looses the periodic structure.
The film of the polymer blend was rinsed with KOH-methanol to remove the telechelic polyethylene oxide resulting in the porous membrane, which was substrantiated by SAXS, SEM, and measurement of surface area by BET method.
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