Electrolyte acrylamide copolymers

The copolymer of acrylamide and ammonium acrylate is used to build viscosity in rinse cycle fabric softeners. This polymer is compatible with nonionic and most cationic surfactants that are used in fabric softener formulations. The polymer is incompatible with anionic surfactants and strong oxidizing agents, and it is sensitive to electrolytes. An example of other cationic polymers useful as thickeners for aqueous acid solutions is described in patent application EP 395282 [24],... 

Copolymers with sites for association in aqueous solutions were pre-pared by copolymerizing acrylamide with N-alkylacrylamides or with the ampholytic monomer pairs sodium 2-acrylamido 2 methylpro-panesulfonate (NaAMPS) and 2-acrylamido-2-methylpropane-dimethylammonium chloride (AMPDAC). The copolymers were characterized by elemental analysis, NMR and Fourier transform infrared spectroscopy, and lowhangle laser and quasielastic lightscattering measurements. Rheological properties were studied as a function of microstructure, molecular weight, polymer concentration, electrolyte concentration, and shear rate. On the basis of those results, a conceptual model that is based on microheterogeneous domain formation in aqueous solutions is proposed. 

Polyampholytes. Ampholytic copolymers (i, 30-35) exhibit interesting viscosity behavior in electrolyte solutions that is quite opposite to the behavior of conventional polyelectrolytes. Recently we prepared high charge density copolymers from the matched, nonhydrolyzable comonomer pairs sodium 2-acrylamide-2-methylpropanesulfonate (NaAMPS) and 2-acrylam-ide-2-methylpropanedimethylammonium chloride (AMPDAC) (1, 33) see structures). 

Copolymers of 2-acrylamide-2-methylpropyldimethylammonium chloride and sodium 2-acrylamide-2-methylpropanesulfonate (AMPDAC-SAMPS) were prepared and their dilute solution properties studied as a function of copolymer composition, temperature, time, pH and added low-molecular-weight electrolytes [39-42]. Equimolar copolymers display a minimal viscosity in pure water and a maximal one in concentrated salt solutions. As the copolymer compositions deviate from an equimolar, charge imbalances increase the hydrodynamic volume of the macromolecules. 

Copolymers of acrylamide with sodium-3-acr y lamido-3-methylbutanoate, the AM/NaAMB series, are polyelectrolytes with high molecular weight. Unlike conventional acrylamide/sodium acrylate copolymers, however, viscosity loss in the presence of electrolytes is relatively low, apparently moderated by intramolecular stiffening effects. The AM/NaAMB copolymers like AM/NaAMPS show no phase separation in aqueous solutions of... 

Fig. 15. Dependence of the free solution electrophoretic mobility /.to on dimensionless charge density for equal M copolymers of acrylic acid and acrylamide. The charge density is controlled by varying copolymer composition while holding the pH high enough (pH 10.5 phosphate electrolyte) to ionize the acrylic acid units fully. From Ref. 46.

Mende M, Petzold G, Buchhhammer UM (2002) Poly electrolyte ctnnplex formation between poly(diallyldimethylammonium chloride) and copolymers of acrylamide and sodium-acrylate. Colloid Polym Sci 280 342-351... 

Since NVP is quite soluble in pure water suspension, polymerization of this monomer is obviously likely only if specialized techniques are used. Monagle [507] claimed that a nontacky, hard, yet water-soluble bead of a copolymer of 80% acrylamide and 20% NVP can be produced in a mixture containing at least 40% tertiary butanol (a nonsolvent for the polymer) in water if electrolytes such as KCl, NH4CI, Na2S04, NaCl, NH4OH, and so on, were added. Ammonium persulfate, potassium persulfate, H2O2, and AIBN were used as initiators. It is also possible to produce cross-linked PVP bead polymer in an aqueous system in the presence of inorganic salts [508,509]. 

Viscometric measurements have revealed a rapid increase in the relative viscosity at a critical surfactant concentration. However, the behaviour depends on the type of poly electrolyte used. As an illustration, Figure 2.20 shows the viscosity-SDS concentration curves for two types of cationic polyelectrolyte JR-400 (cationically modified cellulosic) and Reten (an acrylamide/(j5-methylacryloxytrimethyl)ammo-nium chloride copolymer, ex Hercules). 

In this chapto, we have illustrated the effects of molecular architecture of polysulfobetaines on solution behavior under specilBc environmental conditions of pH, added electrolytes, and polymer concentration. The nature of the comonomer and amount of incorporation of the sulfobetaine within the polymer chain dictate the polymer solubility and solution behavior. Polyampholyte behavior is realized for acrylamide-based systems containing the sulfobetaine moiety. Polyelectrolyte behavior is coupled with polyampholyte behavior for cyclopolymers containing >40mol% sulfobetaine. Incorporation of the sulfobetaine monomer hinders hydrophobic association for the pH responsive copolymers of series TV at low degrees of ionization. 

Poly(ionic liquid) brushes with terminated ferrocene units acted similarly, while the interfacial resistance was probed by hexacyanoferrate [457]. Chemical and electrochemical switching of local pH at an electrode-grafted poly(vinyl pyridine) brush again allowed modulation of hexacyanoferrate chemistiy (Fig. 43) [458]. Octacyanomolybdate was used as catalyst for the oxidation of ascorbic acid [459]. Even heteropolyanions (Keggin ions) could be entrapped in polymer films electrochemicaUy [460]. Further, thermoresponsive or pH-responsive cationic copolymer films modulated the hexacyanoferrate or ferrocenedicarboxyUc acid electrochemistry by temperature or variatimi of pH and perchlorate concentration, respectively [461-463]. Besides these complexes with cationic polyelectrolyte films, electroactive cationic counterions (e.g., the europium couple) interacted with anionic networks [464]. Similarly, copper ions within a PAA matrix [367] allowed the construction of actuators [465]. Besides these binary systems (poly-electrolyte/electroactive counterions), multiresponsive electrode modification with an interpenetrating gel network of poly(acrylic) acid and poly(diethyl acrylamide) allowed the modulation of hexacyanoferrate electrochemistry [368]. 

Single ionic polymer electrolyte based on 2-acrylamide-2-methy 1-1-propane sulphonic acid (AMPS) copolymer... 

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