Copolymerization of acrylamide

Acrylamide copolymerizes with many vinyl comonomers readily. The copolymerization parameters ia the Alfrey-Price scheme are Q = 0.23 and e = 0.54 (74). The effect of temperature on reactivity ratios is small (75). Solvents can produce apparent reactivity ratio differences ia copolymerizations of acrylamide with polar monomers (76). Copolymers obtained from acrylamide and weak acids such as acryUc acid have compositions that are sensitive to polymerization pH. Reactivity ratios for acrylamide and many comonomers can be found ia reference 77. Reactivity ratios of acrylamide with commercially important cationic monomers are given ia Table 3. 

Bio-Gel P materials of Bio-Rad are polyacrylamide beads (45-90 fim in diameter) prepared from copolymerization of acrylamide and N,N -methylenebis-... 

Radical copolymerization is used in the manufacturing of random copolymers of acrylamide with vinyl monomers. Anionic copolymers are obtained by copolymerization of acrylamide with acrylic, methacrylic, maleic, fu-maric, styrenesulfonic, 2-acrylamide-2-methylpro-panesulfonic acids and its salts, etc., as well as by hydrolysis and sulfomethylation of polyacrylamide Cationic copolymers are obtained by copolymerization of acrylamide with jV-dialkylaminoalkyl acrylates and methacrylates, l,2-dimethyl-5-vinylpyridinum sulfate, etc. or by postreactions of polyacrylamide (the Mannich reaction and Hofmann degradation). Nonionic copolymers are obtained by copolymerization of acrylamide with acrylates, methacrylates, styrene derivatives, acrylonitrile, etc. Copolymerization methods are the same as the polymerization of acrylamide. 

The different physical properties, the reactivity of comonomers, and the reaction medium affect copolymerization. The majority of the real processes of copolymerization of acrylamide are complicated. Therefore, copolymerization may not be characterized by the classic equations. The following are the main complicating factors in the copolymerization of acrylamide. 

Heterogeneous copolymerization of acrylamide causes redistribution comonomers between phases I and II. This leads to a change of copolymer composition in phases I and II. As a result, the values of ri and change. This accounts for anomalous widening of the experimental composition distribution curves as compared with theoretical curves. 

Anionic polyacrylamide was prepared by gamma radiation-initiated copolymerization of acrylamid with sodium acrylate in aqueous solution at optimum conditions for the copolymerization [17]. The copolymerization process produces water-soluble poly (acrylamide-sodium acrylate [pAM-AANa] of high molecular weight [17,54]. 

Poly(acrylamide-diallylethylamine-HCl) (cationic polyacrylamide pAM-HCl) was prepared by gamma radiation-initiated copolymerization of acrylamide with di-allylethylamine-HCI in aqueous solution at the optimum composition for copolymerization of acrylamide with diallylamine derivatives [61]. 

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]. 

Figure 3 Effect of dose-rate on the copolymerization of acrylamide with DAEA-HCl. O = Rp = [tj].

Figure 5 Effect of comonomer concentration on copolymerization of acrylamide with EAEA-HCl. O Rp, % = [tj].

From the logarithmic plot of the Arrhenius equation shown in Figs. 8 and 9, the overall activation energy, / p, was calculated to be 0.65 and 0.56 Kcal/mol for AM-AANa and AM-DAEA-HCl systems, respectively. However, the corresponding reported values for gamma radiation induced copolymerization of acrylamide with DMAEM-MC in aqueous solution was found to be 2.0 Kcal/mol [16]. 

T. Siyam, Studies on Gamma Radiation Induced Copolymerization of Acrylamide Sodium Acrylate as Floccu-lant, M. Sc. Thesis, Fac. Sci., Cairo Univ. (1982). 

Qiu et al. [241 have reported the synthesis of macromolecules having 4-tolylureido pendant groups, such as poly(N-acryloyl-N -4-tolylurea-cvi ethyl acrylate) [po-ly(ATU-co-EA)] 18, and poly(N-methacryloyl-A/ -4-tol-ylurea-co-EA) [poly(MTU-co-EA)] 19, from the copolymerization of ATU and MTU with EA, respectively. Graft copolymerization of acrylamide onto the surface of these two copolymer films took place using the Ce(lV) ion as initiator. The graft copolymerization is proposed as Scheme (12). 

Myagchenkov and coworkers (23) reported that no reasonable reactivity ratios could be chosen for the heterogeneous copolymerization of acrylamide and maleic acid in dioxane. 

Microgels may also be produced by dispersion polymerization of multifunctional monomers [276, 277]. Kim et al. synthesized microgels by copolymerization of acrylamide with acryloyl terminated polyethylene glycol macro-monomers in ethanol or in selective solvents [276]. The macromonomer acted... 

In the conventional emulsion polymerization, a hydrophobic monomer is emulsified in water and polymerization initiated with a water-soluble initiator. Emulson polymerization can also be carried out as an inverse emulsion polymerization [Poehlein, 1986]. Here, an aqueous solution of a hydrophilic monomer is emulsified in a nonpolar organic solvent such as xylene or paraffin and polymerization initiated with an oil-soluble initiator. The two types of emulsion polymerizations are referred to as oil-in-water (o/w) and water-in-oil (w/o) emulsions, respectively. Inverse emulsion polymerization is used in various commerical polymerizations and copolymerizations of acrylamide as well as other water-soluble monomers. The end use of the reverse latices often involves their addition to water at the point of application. The polymer dissolves readily in water, and the aqueous solution is used in applications such as secondary oil recovery and flocculation (clarification of wastewater, metal recovery). 

Brandley and Schnaar [140] immobilized a synthetic nonapeptide, Tyr- Ala-Val Thr-Gly Arg-Gly-Asp-Ser, on a polyacrylamide gel, which had been prepared by a ternary copolymerization of acrylamide, bisacrylamide and the acrylic ester of. V-hydroxysuccinimide. They reported that Balb/c 3T3 mouse fibroblast cells (in Hepes-buffered Dulbecco s modified Eagle medium) adhered readily to the peptide-derivatized surfaces, even in the absence of serum, although long-term cell growth required the presence of serum. It was noticed that reference nonapeptide. Tyr-Arg-Leu-Glu-Asp-Pro-Ala-Met-Trp, which has no RGD sequence, failed to promote cell-attachment. 

E.A. Abdel-Razik, Photoinduced graft copolymerization of acrylamide onto styrene-butadiene-acrylonitrile copolymer, J. Photocltem. Photobiol., A, 69(1) 121-124, October 1992. 

In the course of further investigations, charged groups were specially incorporated into PAA networks by copolymerization of acrylamide (AA) with sodium methacrylate (SMA) [10] and also with IV-acryloylsuccinimide, which is easily hydrolyzed in an aqueous medium [11]. Later, the networks of PAA containing cationic ammonium groups [12-14] and quaternized pyridine groups [15] were investigated. 

Figure 5 shows the dependence of the swelling ratio, X, on the acetone content, a, in a water-acetone mixtures of ionized poly(acrylamide) networks the charges onto PAAm chains were introduced by the copolymerization of acrylamide with a low amount of sodium methacrylate [11] (the molar fraction xMNa = 0, 0.004, 0.008, 0.012, 0.016 and 0.024 for series A, B, C, D, E and F, respectively). While in series A and B the dependence of X on composition of the mixtures is continuous, in the other series (C-F) with xMNa > 0.008 a collapse takes place. The extent of the transition and the critical concentration of the acetone at which the collapse appears, ac, increase with increasing xMNa. 

E, A. Abdel-Razik, Photoinduced graft copolymerization of acrylamide onto styrene-butadiene-acrylonitrile... 

Polyacrylamide gels are produced by the copolymerization of acrylamide and the cross-linking agent N,N methylenebisacrylamide. These are supplied by Bio-Rad Laboratories (Bio-Gel P). The Bio-Gel media are available in 10 sizes with exclusion limits ranging from 1800 to 400,000 daltons. Table 3.4 lists the acrylamide gels and their physical properties. 

Polyacrylamide gels are formed by the copolymerization of acrylamide (CH2 =CH-CO-NH2) and a cross-linking comonomer, N, N -methylene-... 

Initially, gels were prepared within the capillary by copolymerization of acrylamide with bisacrylamide [9] as in slab gel electrophoresis. The capillary wall was coated with an acrylate as described above to remove the EOE Thus the gel could also be chemically fixed on the wall. Agarose which can be thermally mobilized has also been used [10]. With these gels the problem discussed above arose. Therefore liquid gels were introduced [11] after they had already been proposed for classical electrophoresis [12]. Some remarks on the properties of the sieving media will be given as the information found in the literature can be very confusing. 

Hernandez-Barajas J, Hunkeler DJ (1997) Inverse-emulsion copolymerization of acrylamide and quaternary ammonium cationic monomers with block copolymeric surfactants copolymer composition control using batch and semi-batch techniques. Polymer 38(2) 449—458... 

Hydrolysis of cationic polyacrylamides prepared from copolymerization of acrylamide and cationic ester monomer can occur under very mild conditions. A substantial loss in cationicity can cause a significant loss in performance in many applications. Copolymers [69418-26-4] of acrylamide and acryloxyethyltrimethylammonium chloride [44992-01-0], CgH16N02(Cl), for instance, lose cationicity7 rapidly at alkaline pH (37). 

The polymerization of acrylamide (AM) and the copolymerization of acrylamide-sodium acrylate in inverse microemulsions have been studied extensively by Candau [10,11,13-15], Barton [16, 17], and Capek [18-20]. One of the major uses for these inverse microlatexes is in enhanced oil recovery processes [21]. Water-soluble polymers for high molecular weights are also used as flocculants in water treatments, as thickeners in paints, and retention aids in papermaking. 

The radical III would be the most stable (kt k2). Post-polymerization and copolymerization of acrylamide- or acrylonitrile-enriched solutions show higher tendency to homopolymerize rather than to copolymerize. 

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