Title

Poly(styrene-b-isobutylene-b-styrene) Block Copolymers and Ionomers Therefrom: Morphology as Determined by Small-Angle X-Ray Scattering and Transmission Electron Microscopy

Document Type

Article

Publication Date

4-1-2000

Department

Polymers and High Performance Materials

Abstract

Solvent-cast films of poly(styrene-b-isobutylene-b-styrene) (PS-PIB-PS) block copolymers and block ionomers were analyzed using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Four block copolymer samples with center block molecular weights of 52,000 g mol(-1) and PS volume fractions (phi(PS)) ranging from 0.17 to 0.31 were studied. Block ionomers were produced by lightly sulfonating the PS outer blocks of the PS-PIB-PS block copolymers. Sulfonation levels were 1.5 and 3.4 mol%, and sodium and potassium counterions were studied. All samples exhibited hexagonally packed cylinders of PS within the PIE matrix. Cylinder spacing was in the range 32-36 nm for most samples, while cylinder diameters varied from 14 to 21 nm. Pored analysis of the scattering data indicated the presence of isolated phase mixing and sharp phase boundaries. (C) 2000 Elsevier Science Ltd. All rights reserved.

Publication Title

Polymer

Volume

41

Issue

9

First Page

3205

Last Page

3211