Dielectric relaxations of Cu(II) salts of ethylene—acrylic acid and styrene—methacrylic acid copolymers

Abstract

Dielectric constant, ɛ′, and the loss, ɛt", of various Cu(II) salts of ethylene-acrylic acid, E-AA, (9.3 mol% AA) and styrene-methacrylic acid, S-MAA, (4.4 mol% MAA) have been measured in the frequency range of 30 Hz to 30 kHz. In the Cu(II) salts of E-AA which form almost dimeric structure of monohydrated copper acetate, two relaxations were observed, β'-relaxation due to a micro-Brownian molecular motion aboveT g andy-relaxation due to a local molecular motion belowT g . By examining molecular motion and estimating number of polar group for the two relaxations, an existence of ion aggregation was comfirmed at the high degrees of neutralization above 20%. In the Cu(II) salts of S-MAA, there were three types of structure of copper complex, monomeric type, monohydrated copper acetate type and pseudo anhydrous copper formate type, the mixing ratio of which depends on preparation procedure of Cu(II) salts. Dielectric behavior of y-relaxation was sensitively influenced by the structure of Cu(II) salt.