Cation Motion in Anionic Fields of the Polyelectrolytic Salts of Ethylenemethacrylic Copolymers

Abstract

The far-infrared spectra of the Li+, Na+, K+, Cs+ salts and acid forms of polyelectrolytic ethylene-methacrylic acid copolymers have been examined in the 800–33-cm−1 region at ambient and low temperatures. A broad band, which shifts to lower frequency as the cation mass is increased, is attributed to cation motion in anionic fields, and the appearance of a low frequency band, whose intensity is related to the cation properties, is assigned to perturbed skeletal motions of a neighboring polymer segment. Models are proposed and analyzed for the vibrational modes involving ion motion. The vibrational force constants for aggregate distortion, as calculated from the observed ion-motion frequencies, are in agreement with such constants computed here employing an ion-multipole potential energy function which does not use these experimental data. The spectral and theoretical results are considered in terms of the molecular interactions of importance in polyelectrolytes and in the physical properties of these materials.

Intravenous itraconazole for prophylaxis of systemic fungal infections in patients with acute myelogenous leukemia and high‐risk myelodysplastic syndrome undergoing induction chemotherapy

“…We can see that maximum value of E correspond to ionomers containing Li + ions. This may be ascribed to the forces between lithium cations and carboxylate groups, which are covalent in nature, which was confirmed by far‐IR investigations 39, 40…”

Infrared Spectroscopic Study of the Binary Blends of Sodium and Zinc Salt Ionomers Produced from Poly(ethylene-co-methacrylic acid)

“…IR or far-IR spectroscopy is a useful technique to investigate the local environments of ionic groups in ionomers, and in EMAA ionomers, the bands due to the asymmetric stretching vibrations of carboxylate groups (ν as (COO - )) in the region 1650−1500 cm -1 can be employed for this purpose. − In the region below 400 cm -1 , the bands due to cation−oxygen vibration in the cation−carboxylate complexes are also interesting because of their sensitivity to ionic aggregations. − The present paper reports IR and far-IR spectroscopic studies of the sodium−zinc mixed ionomers mentioned above, especially concentrating on a new ν as (COO - ) band at 1569 cm -1 , which is absent for individual ionomers and is therefore assigned to carboxylate groups bridging sodium and zinc cations. Temperature-dependent IR studies were carried out over a temperature range from room temperature to 130 °C (403 K).…”

Some properties of styrene‐based ionomers II

“…Ionomers containing Li + ions have distinctive values among the studied polymers. It may be due to the fact that, as indicated by other authors,37, 38 forces between lithium cations and anionic carboxylate groups are covalent in nature, which may cause more dense packing of macromolecules and increase in density.…”