Behaviour of crosslinked and linear poly[1-(3-sulphopropyl)-2-vinyl-pyridinium-betaine] in aqueous salt solutions

Abstract

Linear and crosslinked poly[1‐(3‐sulphopropyl)‐2‐vinyl‐pyridinium‐betaine] (PSPV) samples have been prepared by free radical polymerization of the zwitterionic monomer (SPV) in the absence and presence, respectively, of N,N′‐methylene‐bisacrylamide (MBA). The crosslinked xerogel was swollen to equilibrium at ambient temperature in water and in aqueous solutions of KSCN, KBr and KCl having concentrations ([salt]) extending up to 2 mol dm−3. In aqueous salt the degree of swelling exceeded the value in pure water (0.70), the enhancement in swelling being most marked at low values of [salt]. The content of water within hydrogel increased with salt concentration in swelling medium for low values of [salt] but thereafter fell with further increase in [salt]. In contrast, the salt content within swollen hydrogel displayed a continuous increase with increasing [salt]. The partition coefficient expressing concentration of salt in hydrogel relative to that in swelling medium increased sharply with [salt] at low values, but levelled out to values of 0.8–1.2 at higher values of [salt]. The difference in behaviour among the three salts was not dramatic, but indicated that the affinity of salt for the polymer lay generally in the order KSCN>KBr>KCl. This affinity was confirmed by conductometric determinations of the coefficient of selective adsorption of salt to polymer in solutions of linear PSPV. © 1999 Society of Chemical Industry

Polyampholytes

“…This is most likely caused by intermolecular aggregates being broken apart by screening the attraction between chains with small amounts of added salt. In crosslinked zwitterionic gels,45, 64 swelling increases as salt is added, consistent with the expected screening of attraction between monomers. Such zwitterionic gels have potential for chromatographic separation of proteins 65, 66…”

Dynamics of polyzwitterions in salt-free and salt solutions

“…The details about the synthesis of poly [1-(3-sulphopropyl) betaine-2vinylpyridinium] (PSB) can be found elsewhere. 26,29 Firstly, PS (86 mmol) was stirred with 2VP (95 mmol) in 50 mL distilled toluene at 60 1C for 8 days. The zwitterionic monomers, 1-(3-sulphopropyl) betaine-2-vinylpyridinium (VSB), were isolated by filtration and soaked in toluene for one day and washed with toluene.…”

Synthesis and aqueous solution properties of a well-defined thermo-responsive schizophrenic diblock copolymer

“…12 In general, the attractive electrostatic forces between the polysulfobetaine chains can be attenuated either by adding salt or by raising the temperature to increase the thermal energy of the system. [12][13][14] In contrast, MEMA homopolymer exhibits the typical inverse temperature solubility behavior often observed for neutral water-soluble polymers; its cloud point varies from 34 °C to 49 °C at pH 8, depending on its degree of polymerization. 10 This inverse temperature solubility behavior occurs because increased thermal energies lead to disruption of the hydrogen bonds that are responsible for the initial dissolution of the polymer chains.…”