Synthesis and characterization of polyethylene-based ionomer nanocomposites

A solvent-free reaction of polyethylene-g-maleic anhydride with a tertiary amino alcohol is used to prepare an ammonium carboxylate polyampholyte (PE-g-PA), whose structure is characterized through spectroscopic comparisons to an appropriate model compound. The introduction of ionic functionality results in substantial increases in melt elasticity and viscosity, as well as a demonstrably improved ability to exfoliate onium ion-exchanged montmorillonite clay (NR4+-MM) and to disperse nanosilica (SiO2). Physical and rheological analysis of these nanocomposites suggest that in spite of its relatively small surface area and its capacity to engage only in ion-dipole interactions with PE-g-PA, nanosilica provides a better balance of viscoelastic and mechanical properties when compared with onium-ion exchanged montmorillonite.