Electron spin resonance studies of styrene‐methacrylic acid copolymers neutralized with copper acetate
Electron spin resonance studies of styrene‐methacrylic acid copolymers neutralized with copper acetate
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醋酸铜中和的苯乙烯-甲基丙烯酸共聚物的电子自旋共振研究
DOI：
10.1002/macp.1978.021791125
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
S. Yano
中科院分区：
文献类型：
--
作者：
J. Yamauchi;S. Yano
Polymers having an ionic bond character are one of the interesting subjects in polymer sciences. X-ray diffraction and electron microscope studies, mechanical experiments, and thermal studies have revealed the structure of ionic cross-linking in addition to the various properties influenced by the presence of ionic groups’]. Dielectric measurements were also invoked and presented useful information on the motion of ionic groups in polymers’ 321. In systems containing unpaired electrons, electron spin resonance (ESR) studies can provide us with important results referring to the structure and the molecular motions of polymers. Recently Pineri et aL3] reported a study on butadiene-methacrylic acid copolymers and discussed the evidence for ionic clusters in the acid copolymers neutralized with various salts. ESR was observed on the copolymers completely or partially neutralized with copper acetate. They showed Cu2+-Cu2+ pair configuration which has been proposed to take into account this interaction in monohydrated copper acetate. We have also investigated the properties of ionic groups in polymers and especially the problem of clustering of ionic groups. In ESR measurements we observed new absorption peaks in addition to the resonance lines usually found in butadiene-methacrylic acid copolymers. Another type of Cu2+-Cu2+ interaction may give important information on the structure of “ionomer”. This communication deals only with the copolymers of styrene containing a particular amount of methacrylic acid neutralized with copper acetate.Styrene-rnethacrylic acid copolymers were prepared through bulk polymerization initiated by benzoyl peroxide. The mole fraction of acid was determined by the usual titration method. Then, ionization of the acid copolymers was carried out in benzene solution by adding methanol solution containing copper acetate. The concentration of copper was determined by the ethylenediaminetetraacetic acid (EDTA) titration of nitric acid solution of CuO obtained by combustion. Styrene-rnethacrylic acid copolymer used in the ESR experiment has an acid content of 4, 4mol-% and 79% of the acid groups were neutralized with CU”. ESR spectra were obtained using an X-band spectrometer made by Japan Electron and Optics Laboratory Co. Ltd., JES-ME-3X type, equipped with a 100 kHz field modulation. The magnetic field was calibrated with 0, t mol-% Mn2+ in Mg04’and an X-band frequency counter.
