Spectroscopic studies ionomers

Nicholson, J. W., Brookman, P. J., Lacy, O. M. Wilson, A. D. (1988b). Fourier transform infrared spectroscopic study of the role of tartaric acid in glass-ionomer cements. Journal of Dental Research, 67, 145CM. 

Mauritz, K. A. and Warren, R. M. 1989. Microstructural evolution of a silicon-oxide phase in a perfluorosulfonic acid ionomer by an in situ sol-gel reaction. 1. Infrared spectroscopic studies. Macromolecules 22 1730-1734. 

Kutsumizu, S. Nakumura, Y. Yano, S. Pressure-induced coordination-structural change around zinc(II) in zinc(II)-neutralized ethylene-methacrylic acid ionomers. 1. Infrared spectroscopic studies. Macromolecules 2001, 34, 3033. 

S. Crisp, M.A. Pringuer, D. Wardleworth, A.D. Wilson, Reactions in glass-ionomer cements II. An infrared spectroscopic study, J. Dent. Res. 53 (1974) 1414-1419. 

Eisenbach C D, Hofmann J and MacKnight W J (1994) Dynamic-mechanical and spectroscopic study of ionomer blends based on carboxylated or sulfonated flexible polystyrene and rigid poly(di-acetylenes) with functional side groups. Macromolecules 27 3162-3165. 

Kutsumizu S, Hara H, Tachino H, Shimabayashi K, Yano S (1999) Infrared spectroscopic study of the binary blends of sodium and zinc salt ionomers produced from poly(ethylene-co-methacrylic acid). Macromolecules 32 6340-6347... 

This article shows that microscopy of ionomers is a powerful complementary technique to various spectroscopic and macroscopic techniques like EXAFS and rheology for the investigation of ionomers. If precautions are taken and data are carefully analyzed, microscopy can thus add valuable insights to results from other studies. Because of this, microscopy of ionomers is not only of interest for the scientist trying to imderstand the physics behind ionomer properties and behavior, but also for the engineer attempting to improve or adapt an existing or new ionomer for a desired application. 

Even less is known about ionomer/plasticizer interactions on a molecular level. A variety of scattering and spectroscopic techniques that can probe this level have been mentioned, but they have been applied primarily to the specific case of water in ionomers, and in particular to hjdrated perfluorinated ionomers. At the least, these studies demonstrate the powerful potential of the techniques to contribute to a more complete understanding of structure-property relationships in plasticizer/ionomer systems. For e.xample, to return to the question of the effect of nonpolar plasticizers on the ionic domains how can the decrease in the ionic transition temperature be reconciled with the apparently minimal effect on the SAXS ionomer peaks and with the ESR studies that indicate (not surprisingly) tiiat these plasticizers have essentially no influence on the local structure of the ions Is it due to their association with the hydrocai bon component of the large aggregates or clusters Or if these entities do not exist, as some researchers postulate, what is the interaction between the nonpolar plasticizer, the hydrocarbon component and the ionic domains These questions are, of course, intimately related to the understanding of ionomer microstructure even in the absence of plasticizer. The interpretation of SAXS data in particular is subject to the choice of model used. 

The existence of ion clustering in perfluorinated sulfonate ionomers was first reported by Yeo and Eisenberg in 1975. This phenomenon has been subsequently studied for perfluorinated sulfonate and carboxylate ionomers by many Experimental evidence to support the conclusion that ion clustering occurs in these materials includes thermorheological behavior/ X-ray diffraction results/" " " IR data/ " NMR data,"" " ESR data/ Mossbauer spectroscopic fluores-... 

Spectroscopic and Thermal Studies of Ionic Interactions in Ionomers... 

I, 1980, 76, 2558-2574 L.Y. Levy, A. Jenard and H.D. Hurwitz, Hydration and ion-exchange process in carboxylic membranes. Part 1. Infrared spectroscopic investigation of the acid membranes, J. Chem. Soc. Trans. 1, 1982, 78, 29-36 M. Falk, Infrared spectra of perfluorosulfonated polymer and water in perfluorosulfonate polymer, Perfluorinated Ionomer Membranes, ed. A. Eisenberg, H.L. Yeager, ACS Symposium Series, American Chemical Society, Washington DC, 1982, p. 139 C. Heitner-Wirguin and D. Hall, An infrared study of an anion exchange membrane,... 

Spectroscopic data offer a more local view of the ionomer structure, and can be considered complementary to the small-angle scattering methods. Binding of paramagnetic cations in Nafion ionomers has been studied by multifrequency ESR and simulations (76). Self-assembling of ion-containing polymers, as swollen... 

---