Synthesis and characterization of poly (styrene‐co‐vinyl phosphonate) ionomers

Abstract

Poly(styrene‐co‐diethyl vinylphosphonate) copolymers were synthesized by free radical copolymerization. The ester groups of the copolymers were hydrolyzed to phosphonic acid groups, and the sodium and zinc salts ionomers were obtained by neutralization. The structure and the thermal and viscoelastic properties of the copolymers and ionomers were characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and small‐angle X‐ray scattering. The phosphonate ester lowered the glass transition temperature (Tg) of polystyrene. The free acid derivatives and metal phosphonates increased Tg and produced a rubbery plateau region in the viscoelastic properties due to the formation of a physical network. The acid and salt ionomers exhibited microphase‐separated morphologies and were thermorheologically complex. The phosphonic acid derivatives absorbed relatively little water, even for materials with ion‐exchange capacities greater than 1.0 mEq/g, and were not conductive, which made them unsuitable for application as proton exchange membranes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3628–3641, 2004

Phosphonic acid‐containing polysulfones as anticorrosive layers

“…These results are in agreement with those reported by Meng et al 21 These authors ascribe this effect to strong ionic interactions between the phosphonic acid functions. A similar interpretation was reported by Wu et al, 18 who suggest that "intermolecular hydrogen bonding and strong dipole associations act as physical cross-link and restrict the mobility of the polymer backbone." However, it is well accepted that upon heating at temperatures higher than 180 C, the condensation of phosphonic acid groups may result in the formation of anhydrides bridges which could also contribute to the high T g values.…”

“…This behavior is typical of a plasticizing effect of the alkyl side chains. Such results have already been observed with polystyrene-co-vinylphosphonate 18 and phosphonated polysulfones 19 . Phosphonate ester-containing polymers were first refluxed in concentrated HCl (37%).…”

New highly phosphonated polysulfone membranes for PEM fuel cells

“…However, all phosphonated polymers in their ester form with DP < 2 were found to be soluble in DMF, DMAc and DMSO at room temperature. On the other hand, the hydrolyzed polymers in their acid form with DP < 1 were found to be soluble in DMSO and DMAc at room temperature, whereas polymers with DP = 1 and 1.5, were only swollen in DMSO and DMAc even at 100 • C. This was probably due to the formation of physical crosslinks (Hbonding) which restricted the mobility of the phosphonated PSU backbone [28]. Similar finding was reported by Nuñes et al [13] in the case of palladium-catalyzed phosphonated polysulfones with DP = 0.88 due to the strong ionic clusters in the highly phosphonated materials.…”

Synthesis and characterization of alcogels based on ethylene glycol methyl ether methacrylate-vinyl phosphonic acid copolymers

“…There is a another peak for poly(VPA) at about 200°C. The second Tg can be attributed to a cluster Tg (Tg c ) due to the formation of multiples in macromolecular network as ion-pairs aggregate [27,28]. The Tg c is usually observed in polymers containing ionic groups such as COOH, SO 3 H and their salts.…”