Copolymerization Behavior of Acid‐Base Monomer Systems and Properties of their Corresponding Polymers

Abstract

The copolymerization behavior of mixtures of an acidic and a basic monomer were studied as a function of the monomer feed composition. The four systems investigated in this way comprised APSA/1‐VIm, APSA/4‐VP, APSA/DAMA, and SSA/1‐VIm. The corresponding polyelectrolytes were obtained by free radical polymerization of the monomer mixtures in solution, while the isolated monomeric salts of equivalent amounts of both monomers were prone to spontaneous polymerization. For APSA/1‐VIm, APSA/4‐VP, and APSA/DAMA, a donor‐acceptor relationship was found, whereas for SSA/1‐VIm the SSA was favorably incorporated over all feed ratios. High Tg and complex viscosity data indicated a considerable degree of ionic, thermally reversible crosslinking within the polymers that were thermally stable up to at least 230 °C.magnified image

Copolymerization of 2‐Acrylamido‐2‐methyl‐1‐propanesulfonic Acid and 1‐Vinylimidazole in Ethanol

“…The copolymerization parameters under the acidic conditions were similar to previous results for copolymerizations without pH control ( r AMPS = 0.31, r 1‐VIm = 0.026) 31. The inconsistency of the copolymerization parameter for 1‐VIm was explained by the faster polymerization of 1‐VImH + in acidified monomer mixtures with a high concentration of the basic monomer.…”

“…Like 1‐VIm, other aromatic nitrogen bases, such as 4‐vinylpyridine, might change it from a proton donor to an acceptor by protonation. However, work done by our group, including the copolymerization of AMPS with 4‐vinylpyridine or 2,2′‐(dimethylaminoethyl) methacrylate as well as the polymerization of styrene sulfonate with 1‐VIm, did not show the same effect 31. This can be explained by additional interactions, such as charge transfer between the monomers.…”

“…The viscosity of polymers derived from the basic and neutral solutions increased slightly with increased amount of NaAMPS. Interestingly, the viscosity of copolymers of AMPS/1‐VIm polymerized without pH control was decreased by increasing the amount of AMPS 31. This is due to the repulsive interactions between AMPS – monomers and AMPS – radials at the end of the chain.…”

“…The composition of the copolymers was determined by elemental analysis (Vario EL 2, Elementar Analysensysteme GmbH, Germany) detecting the elements C, H, N, S, and O. Since sulfonic acid functions are known to tightly bind water molecules,31 the copolymers were considered to be composed of three components: the acidic monomer unit, the basic monomer unit, and water. The calculated content of water was based on the content of water determined by TGA measurements.…”

“…Previous work focused on the synthesis and polymerization of the isolated salt AMPS/1‐VImH + and by polymerization of AMPS and 1‐VIm in inverse miniemulsion. However, there was not a clear understanding as to the reaction conditions effect on the polymer and its properties 31–34. We had noticed previously that the pH of the reaction medium influences the properties of the resulting polymer.…”