Ionic bonding in butadiene copolymers. I. Network formation

Abstract

SynopsisThe mechanical effects of association between pendant ionic groups are investigated in series of butadiene-lithium methacrylate copolymers, butadiene-methyl (2-methyl-5vinyl)-pyridinium iodide copolymers, and mixtures of these polyelectrolytes. Thermal and mechanical tests reveal a new transition above T, in the pyridinium copolymers, designated Tt*. Below this temperature the materials behave like covalently crosslinked elastomers. The complex between the metal carboxylates appears thermally dissociable a t all temperatures. The mixing of the oppositely charged polyelectrolytes leads to the formation of more stable intermolecular pyridinium carboxylate links. EXPERIMENTAL Polyelectrolyte Preparation and AnalysisIn a previous publication, l2 the mechanical behavior of three butadienemethacrylic acid copolymers, three butadiene-2-methyl-5-vinyl pyridine

Intravenous itraconazole for prophylaxis of systemic fungal infections in patients with acute myelogenous leukemia and high‐risk myelodysplastic syndrome undergoing induction chemotherapy

“…The results shown in Tables I and II confirm the results of previous studies: the increase in glass transition temperature is much larger in the neutralized form than in the acidic form of the ionomer,1–7 and this increase does not depend on the alkali metal used 29–32…”

“…Eisenberg1 reviewed the effect of ions on the temperature of glass transition ( T g ) of ionomers based mainly on styrene,2 butadiene,3 ethyl acrylate,4 and ethylene 5. It has been shown1–6 that the T g of the ionomer is considerably higher than that of the polymer before the introduction of ions. Although no meaningful correlation has yet been found, the effect seems to become more pronounced as the T g of the host material decreases.…”

Vinylpyridinium ionomers. III. Influence of the matrix glass transition temperature on the dynamic mechanical properties of random acrylate-based systems

“…Indeed, the investigation of their dynamic mechanical properties has shown that the properties of the materials, aside from an increase in the glass transition temperature with increasing ion content, were unaltered by the incorporation of up to 24.2 mol% of vinylpyridinium units. This is in contrast with the results obtained by Otocka and Eirich (3,4), for butadiene-based vinylpyridinium ionomers. Not only did they observe a large increase in the glass transition temperature of the materials with increasing ion concentrations, they also observed the appearance of a second inflexion point in the Young's modulus versus temperature curves and a decrease in the slope of the same curves in the transition regions.…”

“…For personal use only. this investigation will be compared with the results that already exist on butadiene- (3,4), styrene-(I), and ethyl acrylate-based (2) vinylpyridinium ionomers to obtain a better understanding of the effect of the matrix glass transition on cluster formation in vinylpyridinium ionomers.…”

Particulate ionomer films prepared from dispersions of crosslinked polymer colloids: A structure–property study

“…Conventional poly(Bd/MAA) ionomers are well known [2,7,8]. In some cases linear high molar mass copolymers have been prepared using emulsion polymerisation [8]; however those particles were not crosslinked.…”