Deformational, swelling, and potentiometric behavior of ionized gels of 2‐hydroxyethyl methacrylate–methacrylic acid copolymers

Abstract

SynopsisThe deformational, swelling, and potentiometric behavior of ionized water-swollen gels of 2-hydroxyethyl methacrylate (HEMA)-methacrylic acid (MA) c,opolymers used in biomedical and separation applications was investigated. With increasing degrees of neutralization a, the swelling degree strongly increases and the modulus G, decreases. For the copolymers with MA content 1 30 mole-%, the dependence of G, on a passes through a minimum. Comparison of the results with the modified theory of rubber elasticity shows that the decrease in G, at low concentrations of charges on the chain is controlled mainly by the degree of swelling. At higher a, both the finite extensibility of network chains, caused by a high degree of swelling, and electrostatic interactions contribute to G,. The dependence of the interaction parameter x on the volume fraction of polymer in the gel, uz, is independent of a and closely resembles the dependence obtained for other hydrophilic polymers.

Elasticity of ion‐exchange resin beads in solvent mixtures

“…Equation (2) is based on the assumption of affine swelling and it was verified experimentally for weakly ionized polyelectrolyte gels swollen in water, 4,8,15 but some deviations were observed at high degrees of ionization. 2 In eq. (2) the G 0 corresponds to the modulus at a hypothetical reference state and it has no correlation with the real modulus of the dry resin, as shown later.…”

“…1 On the other hand, the elasticity of strongly swellable hydrogels has been extensively studied; for instance, slightly crosslinked homopolymer and copolymer gels of acrylic acid, methacrylic acid, and acrylamide have been quite throughly surveyed. [2][3][4][5][6][7][8] The elastic modulus in the swollen state is at least one decade smaller for the hydrogels than for the more heavily crosslinked ion-exchange resins. On the other hand, elastic moduli comparable in magnitude to the ion-exchange resins have been reported, for example, for swollen poly(styrene-codivinylbenzene) (PS-DVB) copolymers, 9 a swollen crosslinked polysaccharide, 10 and swollen gels containing OSO 3 Ϫ or OCH 2 SO 3 Ϫ functional groups.…”

Wettability and ζ potentials of a series of methacrylate polymers and copolymers

“…The synthesis of methaerylate polymers and copolymers is well known (7)(8)(9)(10)(11)(12)(13)(14). The methacrylate polymers and copolymers used in this study were poly(methyl methacrylate) (MMA), poly(hydroxyethyl methacrylate) (HEMA), and MMA/HEMA copolymers (mole ratios (%): 75/25, 50/50, and 25/75), copolymers of MMA with methacrylic acid HOGT (97 MMA/3 MAA and 85 MMA/15 MAA), and with trimethylaminoethyl methacrylate-HCI salt (97 MMA/3 TMAEMA-C1 and 85 MMA]I5 TMAEMA-CI), copolymers of HEMA with MAA (97/3 and 85/15) and with TMAEMA-CI (97/3 and 85/15), poly(nbutyl methacrylate) (BMA), poly(n-hexyl methacrylate) (HMA), and poly(n-dodecyl methacrylate) (DDMA).…”

A study of the copolymerization of hydroxyethyl methacrylate and tetrahydrofurfuryl methacrylate

“…For example, an increase in the hydrophilicity of PHEMA was achieved by copolymerization with 2,3-dihydroxypropyl methacrylate 1 and a decrease in hydrophilicity was achieved by the incorporation of furfuryl acrylate, 2 thereby increasing and decreasing the range of the equilibrium water content, respectively. Comonomers with anionic fixed charges, such as methacrylic acid (MAA), 3,4 have been introduced into PHEMA to minimize the effect of calcification, a major disadvantage of implants, while cationic membranes have been synthesized using 2-(N,N-diethylamino)ethyl methacrylate 5,6 to enhance the permeation of salts.…”