Precise Acid Copolymer Exhibits a Face-Centered Cubic Structure.

A linear polyethylene precisely functionalized with geminal phosphonic acid pendants on every 21st carbon atom exhibits face-centered cubic (FCC) packing of acid aggregates. X-ray scattering from isotropic films result in higher-order scattering peaks used to determine the lattice parameter at room temperature ( = 4.19 nm) and above the melting temperature of the polyethylene matrix ( = 4.

Ionic aggregate structure in ionomer melts: effect of molecular architecture on aggregates and the ionomer peak.

We perform a comprehensive set of coarse-grained molecular dynamics simulations of ionomer melts with varying polymer architectures and compare the results to experiments in order to understand ionic aggregation on a molecular level. The model ionomers contain periodically or randomly spaced charged beads, placed either within or pendant to the polymer backbone, with the counterions treated explicitly. The ionic aggregate structure was determined as a function of the spacing of charged beads and also depends on whether the charged beads are in the polymer backbone or pendant to the backbone.

Nanoscale morphology in precisely sequenced poly(ethylene-co-acrylic acid) zinc ionomers.

The morphology of a series of linear poly(ethylene-co-acrylic acid) zinc-neutralized ionomers with either precisely or randomly spaced acid groups was investigated using X-ray scattering, differential scanning calorimetry (DSC), and scanning transmission electron microscopy (STEM). Scattering from semicrystalline, precise ionomers has contributions from acid layers associated with the crystallites and ionic aggregates dispersed in the amorphous phase. The precisely controlled acid spacing in these ionomers reduces the polydispersity in the aggregate correlation length and yields more intense, well-defined scattering peaks.

Precision sulfonic Acid ester copolymers.

Linear ethylene copolymers containing sulfonic acid ethyl esters precisely spaced on every 21st carbon have been synthesized using metathesis polycondensation chemistry. These precision structures with one directly attached and one aromatic spaced sulfonic acid ester are synthesized with the goal of tailoring layered higher order morphologies in contrast to conventional clustered ionic polyolefins. Primary structural characterization confirms the precision polymer structures.