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The membrane permselectivities of several bilayer perfluorinated ionomer chlor-alkali membranes have been measured using a sodium ion radiotracer method with an automated laboratory electrolysis cell. The influence of solution concentrations, electrode-membrane gap, and solution mixing were evaluated for membranes which differed with regard to fabric reinforcement and surface smoothness. Results indicate that these cell and membrane-related factors all influence membrane permselectivity in an operating cell, with certain practical consequences. The underlying reasons for this complex behavior are discussed.

The structural properties of the polymers poly(methyl methacrylate-co-methacrylic acid) P(MMA-co-MAA), poly(styrene-co-methacrylic acid) P(S-co-MAA), and poly(styrene-co-p-sulfonic acid) P(S-co-SSA) were studied using small-angle X-ray scattering methods. Evidence for ionic aggregation in the dry state and phase separation in the wet state is found for some of the systems. The thin film membrane properties of these polymers as well as poly(styrene-co-acrylic acid) P(S-co-AA) and poIy(vinylcyclohexaneco-acrylic acid) P(VCH-co-AA) were evaluated. The conductivity and the properties of sorbed water were evaluated as a function of increasing ionic content. For each polymer system, an abrupt insulator to conductor transition was found, at water contents which indicate that ionic-aqueous conducting regions in the polymers are randomly distributed whether or not the polymer is phase-separated. The hydrogen bonding of sorbed water in these polymers was studied using near-infrared spectroscopy and compared to that in other hydrophilic polymers.

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The thermal behaviours of zinc, cobalt, nickel and copper acrylates and their polymers were investigated. It was found that the decompositions of these compounds are complex processes. The main decomposition of the monomer was preceded by thermal polymerization. The thermal effect of this reaction was greater for zinc acrylate than for the other salts. The reaction orders and activation energies of decomposition of the monomers and the polymers were calculated and the differences discussed.In recent years metal-containing monomers and polymers have been subject to increasing interest. This is due to a number of valuable properties shown by coordination polymers and ionomers. The area of applications of such polymers is very broad and among their characteristic features are chemical resistence and thermal stability. Metal derivatives of polymers containing COOH groups are among the best known.The thermal behaviours of some monovalent and divalent metal acrylates have been reported [1 ]. Monomers containing divalent transition metals may be especially interesting for the preparation of coordination polymers and ionomers. In the present paper, therefore the thermal decompositions of zinc(ll), cobalt(ll}, nickel{ll) and copper(ll} acrylates and of their polymers were investigated and the results compared. Experimental Preparation of metal acrylatesMetal acrylates were prepared by the reaction of acrylic acid (5-10 wt.% stoichiometric excess) with zinc oxide, basic cobalt carbonate, basic nickel carbonate and cupric hydroxide, respectively, in toluene suspensions at 40-50 ~ . The reactions were carried out for 5 h, with gradual addition of the reactants and with constant stirring. The evaporated toluene lost from the reaction vessel was constantly replaced. Water formed in the reactions was removed as an azeotropic mixture with toluene.7inc, copper and cobalt acrylates were washed with toluene and then dried in a vacuum drier at 40-50 ~ Nickel acrylate, after a preliminary drying, was ground, washed with acetone and finally vacuum-dried like the other monomers.