Infrared Studies of Ionic Aggregation of Ethylene- and Butadiene-Based Ionomers

Abstract

An infrared spectroscopic investigation of the Na+, K+, Rb+, and Cs+ salts of ethylene-and butadiene-methacrylic acid copolymers has been carried out. The absorption due to the asymmetric stretching mode of the carboxylate ion contains two components: one at 1550 cm-' and another at 1565 cm-I. The ratio of peak intensities of these bands depends upon ion concentration, the nature of the cation, and temperature. It is concluded that the ion pairs in these copolymers are likely to exist in at least two types of ionic aggregates of different structures. Infrared dichroism studies established that the dichroic ratios of the 1550-and 1565-cm-' bands depend on ion concentration in copolymers. The model systems, anhydrous salts of fatty acid, were also studied. A combination low-angle x-ray scattering and infrared data leads to a probable model of the ordered structure existing within ionic clusters.

Infrared Spectral Studies on Coordination Structure and Oxidation−Degradation for Cobalt(II) Salts of Ethylene−Methacrylic Acid Copolymer and Their Complexes with an Organic Amine

“…Figure shows IR spectra in the region of 1100−1800 cm -1 at room temperature for EMAA- x Co, and Table lists the peak frequencies for EMAA- x Co and EMAA-0.6Co-0.6BAC and their assignments. ,− ,− EMAA- x Co shows a CO stretching band of unneutralized carboxylic acid dimers [ν(CO)] near 1700 cm -1 and asymmetric [ν as (COO - )] and symmetric COO - stretching bands [ν s (COO - )] near 1600 and 1400 cm -1 , respectively. With increasing x , the intensity decreases in the ν(CO) band while it increases in the ν as (COO - ) and ν s (COO - ) bands.…”

“…Infrared (IR) spectroscopy is a useful technique to investigate some local environments of ionic groups in ionomers . To date, the coordination structure of ionic groups has been studied for ethylene ionomers, − and it has been pointed out that the coordination structure rather sensitively changes with the state of the ionic aggregates. This paper presents IR spectral studies for ethylene−methacrylic acid copolymer (EMAA) neutralized with Co(II) and its complex salts with an organic amine, 1,3-bis(aminomethyl)cyclohexane [1,3-(NH 2 CH 2 ) 2 C 6 H 10 ] (BAC).…”

Tailoring the ionic association and microstructure of ionomers with various metal salts

“…The peaks in this range were ascribed to the local structures of ionic groups from multiplets (low wave numbers) to clusters (high wave numbers). These two bands were related to the asymmetric stretching vibration of the carboxylate groups in the ionic multiplets and in the ionic clusters, respectively,22–25 and as the proportion of metal salt in the multiplets increased, the local structure became more complex.…”

Effect of Blending on the Structure of Thermoplastic Interpenetrating Polymer Networks

“…[18] On the other hand, Andreeva et al [19] assigned the carboxylate absorption at 1550 cm 21 to the asymmetric vibration of carboxylate ion in ionic multiplets and the same vibration at 1565 cm 21 in ionic clusters. The absorption at 1565 cm 21 is absent in the spectrum of S-b-AA(K þ ) (see Fig.…”