Structure and Properties of Ionomers

Ionomers, that is polymers containing a low concentration of charged units along the chain, have been the subject of increasing interest during the past twenty years. The presence of ionic groups in the poly­ mer changes some of its properties dramatically. Increases in the modu­ lus and the viscosity of several orders of magnitude have been observed, and changes in the glass transition of hundreds of degrees are possible. In addition, diffusion coefficients can be modified drastically. These changes are due primarily to the presence of reversible ionic cross­ links in these materials. Because of the low dielectric constant of most organic polymers, the ions or ionic dipoles tend to aggregate ; this aggregation process, however, is limited, because the ionic groups are covalently bonded to the organic chain. Host of the fundamental research done on these materials has been devoted to a determination of the extent of association, the structure of the aggregates, the limi­ ting factors, and the correlations between molecular and supermolecular structure and the resul ting properties.

Contenu

Available Ionomers.- A review and critical analysis of theories of polar/ nonpolar aggregation in ionomers.- Simple considerations on the morphology of ionomers.- Statistical mechanics of ion-pair association in ionomers.- The EXAFS spectroscopy applied to the ionic aggregates of HTP.- EXAFS analysis of ion containing polymers.- Chemistry in ionomers.- Chromium (III) and cobalt (II) aquo complexes in PFSA (nafion) Ionomer films.- EPR of Mn2+ , Fe3+ and Cu2+ in ionomers.- Magnetization and susceptibility of ion-containing polymers.- Electronic spectra and photophysical properties of ions as probes for the properties and structure of perfluorinated ionomer membranes.- Structural studies of ionomers by infrared spectroscopy.- An NMR study of a,?-dicarboxylatopolybutadiene.- Structure of ionomers: use and abuse of SAXS.- Small angle neutron scattering studies of ionomers in the bulk state.- Labelling and misinterpretation.- Roundtable discussion concerning the relations between the results obtained from local and macroscopic studies.- Viscoelastic behavior of ionomers in bulk and solution.- Dielectric and related molecular processes in ion containing polymers.- Spin-glasses versus glassy glasses.- Glass transitions in multicomponent systems.- A review of the glass transition in surlyns and polypentenamer ionomers.- Ionic elastomers.- 'Glass transitions' in ionomer membranes.- Glass transition temperatures in styrene ionomers and their blends.- Glass transition behavior of carboxylato-telechelic polymers as models of the related ionomers.- Round table discussion on glass transition and dynamic mechanical properties of ionomers.- Water absorption studies of carboxilic and sulfonic ionomers: correlations with their microstructure.- Effect of solvents on structure and properties of ionomers.- Relationships between polymer structure and ion diffusion in perfluorinated ionomer membranes.- Review: Ionomer solution behavior.- Gelation and phase separation of solutions of halato telechelic polymers.- Gelation theory for ionomer solutions.- Gerneral discussion following the session on solutions and gels.- Ionomer applications including ionic elastomers and polymer/ fluid additives.- Ionomers for adhesives, antistatics, magnetic recording, and imaging systems.- Committee report on solved and unsolved problems in ionomer research.- Committee report on the future applications of ionomers.- Committee report on problems of synthesis of ion-containing polymers.- Committee report on ionomer characterization.- The microphase separation in polyurethane ionomers.- Structure and molecular motion in complex salts of ethylene-methacrylic acid copolymer with 1,3-bis-amino- methylcyclohexane and/or zinc (II).- Conductivity and thermally stimulated processes in ionomers based on SIS block copolymers.- A study of water in perfluorosulphonate membranes using near infrared spectroscopy.- The sodium salts of sulfonated polyaryletheretherketone (PEEK): preparation and characterization.- Effects of inter- or intra-molecular interactions on dynamics of ionomers in dilutes solutions.- Solution properties of polystyrene-based ionomers in polar and low-polarity solvents.- Polystyrene zwitter ionomers.- Sulfonatopropylbetain random copolymers: zwitterionic analogues of ionomers.- Ion density as a structure-determining factor in ionenes.- Dilute solution properties of ionomers obtained from EUDRAGIT-S.- Dynamic mechanical properties of concentrated solutions of a polystyrene ionomer in a styrene oligomer.- Ionomers from sulfonated polynorbornene.