Acrylamide in aqueous solution

The polymerization of acrylamide in aqueous solutions in the presence of alkaline agents leads to the ob-tainment of partially hydrolyzed polyacrylamide. The polymerization process under the action of free radicals R (formed on the initiator decomposition) in the presence of OH ion formed on the dissociation of an alkali addition (NaOH, KOH, LiOH), and catalyzing the hydrolysis can be described by a simplified scheme (with Me = Na, K, Li) ... 

III. KINETICS OF RADIATION-INDUCED POLYMERIZATION OF ACRYLAMIDE IN AQUEOUS SOLUTION... 

The reported values for the exponent of the dose-rate for the polymerization rate in gamma radiation-induced copolymerization of acrylamide with methyl chloride salt of A, A -dimethylaminoethyl methacrylate (DMAEM-MC) in aqueous solution was found to be 0.8 [16]. However, the dose-rate exponent of the polymerization rate at a lower dose-rate was found to be slightly higher than 0.5 for gamma radiation-induced polymerization of acrylamide in aqueous solution [45,62]. 

It was found that [Ru(l,10 phenanthroline)3] and [Ru(2,2 -bipyrazine)3 ] complexes can photosenstize the polymerization acrylamide in aqueous solution [57]. A similar mechanism to that shown in Scheme (34) is suggested. However, maleic acid (MA) comonomer is used as a strong photoelectron doner in the [Ru(2,2 -bipyrazine)]-acrylamide/TEA relay system. The high-molecular weight, 7.7 x 10 g/mol, of the acrylamide-maleic anhydride random copolymer is obtained. 

Acrylamide in aqueous solution has been chosen as the grafting agent by some authors (38,87,88), as well as acrylonitrile (59). 

Fig. 12. Copolymerization DADMAC/acrylamide in aqueous solution. Influence of the initial monomer concentration on the copolymer composition (— data taken from [64] data taken from [65])...

Indeed, photopolymerization of acrylamide in aqueous solution on cell-GEHMP gives cellulose with the surface covered by a poly acrylamide) gel. Similarly, UV initiated polymerization of 2-hydroxyethyl acrylate, 2-(dimethylamino) ethyl methacrylate and A -vinylpyrrolidone carried out with the above functionalized Si(>2 results in the formation of a surfece polymer coating. 

Polymerization of Acrylamide in Aqueous Solution by a Continuous Process... 

A laboratory scale, continuous process for the polymerization of acrylamide in aqueous solution is described. The reaction conditions can be held constant within narrow limits and the effect of small changes in individual variables, such as temperature, initiator concentration, and chain transfer agent concentration, can be quantitatively ascertained. Some experimental results are presented showing the effect of these factors on the molecular weight of the polymer. The data are examined vis-a-vis some theoretically derived equations. 

Dispersions stabilized by poly(acrylic acid) and poly(acrylamide) in aqueous solutions fiocculate on cooling in the presence of suitable electrolytes. The LCFTs were found to be essentially independent of the molecular weight when the molecular weights of both polymers were varied over an order of magnitude (see Table 6.1). 

POLYMERIZATION CONDITIONS Free-radical polymerizations of acrylamide in aqueous solutions and solid-state polymerization of crystalline acrylamide with ionizing radiation. 

YAM Yamazaki, Y., Tada, T., and Kunugi, S., Effect of acrylic acid incorporation on the pressure-temperature behavior and the calorimetric properties of poly(JV-isopropyl-acrylamide) in aqueous solutions. Colloid Polym. Sci., 278, 80,2000. 

NU2 Nuopponen, M., Kalliomaeki, K., Aseyev, V., and Tenhu, H., Spontaneous and thermally induced self-organization of A-B-A stereoblock polymers of Y-isopropyl-acrylamide in aqueous solutions, Macromolecules, 41, 4881, 2008. 

The solvating envelope of the polymer chain can increase when the polymer-solvent interaction (solvent quality) increases with the temperature. The rising solvation of the chain leads to an expansion of the polymer coil and therefore to an increasing intrinsic viscosity. Figure 5.7 shows this increase of the intrinsic viscosity with the temperature for poly(acrylamide) in aqueous solution. The zero-shear viscosity of the same sample decreases with the temperature in Fig. 5.5. 

Dainton FS, Tordoff M. The polymerization of acrylamide in aqueous solution part 3. The hydrogen peroxide photosensitized reaction at 258°C. Trans. Faraday Soc. 1957 53 499. 

The reaction is very fast. For example, for the (O-hexenyl radical k = 4-l0 l/(mol s) (298 K, H2O). Chains of radical polymerization terminate on the ion-reducing agents due to reduction. Below we present k for chain termination on the ions for the polymerization of acrylamide in aqueous solutions (298 K)... 

Suspension Copolymerization of Styrene and Acrylonitrile 41-11. Suspension Copolymerization of Acrylamide and Acrylic Acid 41-12. Polymerization of Acrylamide in Aqueous Solution 41-13. Continuous-Solution Polymerization of -Vinylpyrrolidone... 

Rigolini et al. (2010) reported microwave-assisted NM radical polymerization of acrylamide in aqueous solution. Reasonable results were obtained for a nitroxide-mediated radical polymerization with a combination of a conventional hydrosoluble radical initiator and a phosphorylated nitroxide. The microwave enhancement of the polymerization was found to depend on the mode of irradiation, whether it is a dynamic (DYN) mode or pulsed power mode (SPS). 

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