Surface - Active and Complexforming Copolymers of Sodium 2-acrylamido-2-methylpropanesulfonate with Ethyleneglycol Vinyl Ether

Abstract

<p>A new water-soluble polyelectrolyte - the copolymer of sodium 2-acrylamido-2-methylpropanesulfonate and ethylene glycol vinyl ether has been synthesized by free-radical copolymerization in aqueous medium. Synthesis of the linear structure water-soluble copolymer of sodium 2-acrylamido-2-methylpropanesulfonate (Na-AMPS) and ethylene glycol vinyl ether (EGVE) has been confirmed by IR spectroscopy method, potentiometric titration and viscometer. The concentration behavior of the reduced viscosity of copolymer solutions that is typical for polyelectrolytes has been revealed. The reactivity ratios for the copolymerization of the monomers estimated by the Mayo–Lewis method have indicated lower reactivity of ethylenglycol vinyl ether in comparison with sodium 2-acrylamido-2-methylpropanesulfonate. Also it was shown the decrease of reaction’s relative rate with an increase of molar fraction of EGVE in the initial mixture of monomers. Adsorption at the air-water solution interface was studied by measure of surface tension (σ) in order to determine the surface properties of new copolymers of ethyleneglycol vinyl ethers – sodium 2-acrylamido-2-methylpropanesulfonate. It was shown that copolymers of sodium 2-acrylamido-2-methylpropanesulfonate and ethylenglycol vinyl ether have higher surface activity compared to sodium 2-acrylamido-2-methylpropanesulfonate homopolymer. The isotherm of copolymer’s surface tension based on equilibrium value of σ was constructed together with the isotherm of surface tension water solution poly- Na-AMPS. Based on isotherms the surface activity on Rebinder (G<sub>Re</sub>) for poly- Na-AMPS and copolymer Na-AMPS-EGVE was determined. The values of polymer’s standard free energy of adsorption (Δ<sub>ads</sub>G<sup>0</sup><sub>298</sub>) were calculated in order to identify the causes and mechanism of change in surface activity and adsorption. Results show that the gain in standard free energy adsorption in the transition from homopolymer to copolymer Na-AMPS-EGVE is about 4 kJ/base-mole. Interpolymer reaction of the Na-AMS–EGVE copolymer with poly- <em>N,N</em>-dimethyl-<em>N,N</em>-diallylammonium chloride (PMAAC) has been studied. Higher surface activity of mixtures of copolymer and PMAAC than of individual polyelectrolytes was discovered. This effect testified to the formation of interpolymer complex of the Na-AMS–EGVE copolymer with polycations due to electrostatic interactions.</p>