Synergistic enhancement in mechanical properties and microstructure of homoblends made of poly(styrene-co-styrenesulfonic acid) and poly(styrene-co-4-vinylpyridine)

Morphology and deformation behavior of polymer blends made of poly(styrene-co-styrenesulfonic acid) and poly(methyl methacrylate-co-4-vinylpyridine)

“…This prevents premature crack initiation, produces larger plastic strains and energy absorption, and thereby leads to more fracture-resistant and tougher polymers. Although our results on the deformation behavior were obtained on thin films under plane stress conditions, which may differ from those obtained on bulk specimens under plane strain conditions, previous results on ionomers [2] and homoblends [13] have demonstrated enhanced mechanical properties when the deformation mode of thin films changes from crazing toward shear deformation. Hence, introduction of sufficient intermolecular ionic interactions into two otherwise immiscible polymers, can alter deformation and mechanical behavior in a favorable manner.…”

“…The ion-ion interactions between the sulfonate ions and the pyridinium cations provide an additional increase in entanglement strand density above that provided by typical chain entanglements, although the effectiveness of ion-ion interactions (ionic cross-links) is less than that of covalent cross-links. The effects of enhanced strand density on both deformation behavior and mechanical properties of these homoblends has been reported [12,13]: the deformation mode changed from crazing only to crazing plus an increasing amount of shear deformation as the ion content was increased; and both tensile strength and toughness rose to values well above those of either component of the blend (synergism). To the best of our knowledge, this was the first report regarding the effect of ionic cross-links (due to ionion interactions) on deformation behavior of polymer blends.…”

The effect of ionic cross-links on the deformation behavior of homoblends made of poly(styrene-co-styrenesulfonic acid) and poly(styrene-co-4-vinylpyridine)

“…The multiple-deformation behavior is important in increasing toughness of polymers, as it limits the growth and breakdown of crazes, prevents premature crack initiation, and favors larger plastic strains and increased energy absorption. Our results suggest that bulk mechanical properties may also be enhanced by the introduction of intermolecular ionic cross-links (bonding) [27], even though our observations of deformation behavior were obtained on thin films under plane stress conditions, while observations on bulk specimens are obtained under plane strain conditions. Enhanced bulk mechanical properties have been reported for glassy ionomers, in which similar changes in the deformation mode have been made [6,9].…”

“…the average values of toughness and tensile strength are higher than values expected based on the rule of mixtures, and values of both properties are increased with the interacting group content. Details of the bulk mechanical properties study are reported in a separate article [27].…”

Tangible plasticization/filler effects of sodium salts of dimer acids on the mechanical properties of styrene ionomers

“…3,25 This leads to more ion pairs per multiplet of the PSSNa ionomer, compared to those of PSMANa ionomer of the same ion content. At this point, it should be mentioned that the ion-hopping is related to the strength of interactions between ion pairs in the multiplets and is one of the cluster glass transition mechanisms: 3,4,[26][27][28][29][30][31][32][33] When the ion-hopping occurs, the storage modulus of the ionomer starts decreasing. Naturally, the more ion pairs per multiplet and the stronger interactions between ion pairs in the multiplets of the PSSNa ionomer make the ion-hopping occur at higher temperatures (i.e.…”