Structure‐property behavior of elastomeric segmented PTMO–ionene polymers. II

Abstract

SynopsisA series of segmented ionene polymers based on the reaction of qw-bis(dimethy1 amino)polytetramethylene oxide with various dihalide compounds were investigated with respect to their structure-property behavior. The placement of quaternary ammonium ions and halide counterions along the polymer chains was varied by changing the molecular weight of the PTMO soft segment and the structure of the dihalide linking agent. The techniques of dynamic mechanical spectroscopy, thermal analysis, small angle X-ray scattering, and stress-strain behavior analysis were applied. For the case when the PTMO soft segment was amorphous, the ambient temperature properties of these materials displayed low modulus, high strength, and high elongation elastomeric behavior with tensile strength enhanced by the strain-induced crystallization of the PTMO. A high level of phase separation existed between the dihalide component relative to the PTMO soft segment. Due to the Coulombic association of the ionene species, these materials displayed many similarities to the segmented urethane ionomers. In particular, distinct domain structure was noted by SAXS, whose dimensional scale was similar to the segmented urethanes. It was also shown, however, that the driving forces for the microphase separation was caused by favorable electrostatic or Coulombic interactions in contrast to segment-segment incompatibility features as in the segmented urethanes.

Segmented Poly(tetramethylene oxide) Zwitterionomers and Their Homologous Ionenes. 1. Synthesis, Molecular Characterization, and Thermal Stability

“…In spite of some scatter of the experimental points, the data related to all the ionenes under study, whatever the lengths of the PTMO precursor and of the short bifunctional segment, are fairly consistent with a selectivity of the demethylation reactions = 0.97 ± 0.01: see Figure 4. In the same way, the experimental data related to the unique sample of segmented ionene carrying only one ammonium site between the PTMO segments, Af*w = 23 and N^. = 20, are compatible with a selectivity of 0.98, taking into account the experimental accuracy (calculated N^, = 18.6).…”

Segmented Poly(tetramethylene oxide) Zwitterionomers and Their Homologous Ionenes. 2. Phase Separation through DSC and Solid State 1H-NMR Spectroscopy

“…(iii) Finally, for T i = 25 °C, crystallization can be detected only after an annealing for at least 1 week. Very slow crystallization kinetics at room temperature have already been noticed on some segmented PTMO ionenes …”

“…•influence of the chemical structure of the polar units and, more specifically, comparison between homologous zwitterions and ion pairs characterized by identical structures of the charged sites (zwitterionomers versus ionenes) and comparison with literature data related to similar PTMO segmented ionenes − …”

Poly(propylene glycol)‐based ammonium ionenes as segmented ion‐containing block copolymers

“…Charge density will influence the thermal and mechanical properties of ionenes 44. To investigate the effect of charge density on the mechanical properties of PPG ionenes, an additional 1,12‐dibromododecane monomer was added to the reaction mixture.…”