Abstract
A series of halato-telechelic butadiene and isoprene polymers have been studied as model compounds for the more complex ionomers. Small-angle X-ray scattering (SAXS) measurements have been conducted over a wide scattering vector range as a function of the metal cation, degree of neutralization, swelling by both polar and nonpolar solvents, molecular weight, and temperature. It has been found that the characteristic SAXS intensity profile is governed principally by the configuration of the polymer molecule between the ionic groups located at the ends of each chain whereas the nature of the cation plays only a secondary role. Provided the chain length is well-defined, i.e., provided there is a narrow molecular weight distribution, there is a nearly complete microphase separation between the ionic groups and the hydrocarbon chain. The ionic aggregates can be adequately described as multiplets that are surrounded by a volume from which other ionic domains are excluded and are arranged in a liquid-like manner in space. No evidence was found for ionic clusters or a critical concentration and temperature of multiplet formation. © 1986, American Chemical Society. All rights reserved.