Electron spin resonance (ESR) spectroscopy has been used to obtain
information on chain
mobility in spin-doped poly[styrene-co-(sodium
methacrylate)] random ionomers. The results show
that
spin probe molecules randomly dispersed in ionomers respond to the
matrix glass transition. However,
when the probe molecules are anchored to the ionic multiplets, their
mobility is reduced, indicating that
the polymer segments adjacent to the ionic multiplets are constrained,
and their mobility is restricted.
Significant motions of the probe molecules start only when the
kinetics of the ion-hopping process becomes
relevant. Plasticization of the ionomers with polystyrene
oligomers allowed for the simultaneous
observation of two different mobility regimes, assigned to the matrix
and cluster phases. These findings
support the suggestion, which is a major component of the EHM model for
the morphology of random
ionomers, that regions of restricted mobility exist around the ionic
multiplets.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.