Partially hydrolyzed acrylamide

CA 71, 14740u(l969) [Aqueous slurries of inorg oxidizer salts thickened with mixts of partially hydrolyzed acrylamide polymers copolymers and NH4 or alkali metal acrylates are described. Thus, a compn was prepd from water 17.9, propellant 34.8, AN 21.9, NaN03 12.9, ethylene glycol 10.9, pine oil 0.1, 22%... 

A partially hydrolyzed acrylamide gel underwent a phase transition in acetone/ water mixtures [21]. The main polymer-polymer affinity is due to the van der... 

E.I. duPont deNemours and Company Water-Bearing Explosives Thickened with a Partially Hydrolyzed Acrylamide Polymer... 

A partially hydrolyzed acrylamide gel underwent a phase transition in acetone/... 

The most commonly used polymers are partially hydrolyzed polyacrylamides (32). The optimum degree of hydrolysis depends on the apphcation, injection water composition, and reservoir conditions (33,34). More salt-tolerant acrylamide copolymers may permit this technology in higher salinity injection water (35). Eield apphcations of cross-linked xanthan gum have also been reported (36). 

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) ... 

Many synthetic water-soluble polymers are easily analyzed by GPC. These include polyacrylamide,130 sodium poly(styrenesulfonate),131 and poly (2-vinyl pyridine).132 An important issue in aqueous GPC of synthetic polymers is the effect of solvent conditions on hydrodynamic volume and therefore retention. Ion inclusion and ion exclusion effects may also be important. In one interesting case, samples of polyacrylamide in which the amide side chain was partially hydrolyzed to generate a random copolymer of acrylic acid and acrylamide exhibited pH-dependent GPC fractionation.130 At a pH so low that the side chain would be expected to be protonated, hydrolyzed samples eluted later than untreated samples, perhaps suggesting intramolecular hydrogen bonding. At neutral pH, the hydrolyzed samples eluted earlier than untreated samples, an effect that was ascribed to enlargement... 

As far as neighboring group inhibition is concerned, sequence distribution can play an important role, e.g. Morowetz [5] showed that partially hydrolyzed polyacrylamide hydrolyzes more slowly than an acrylic acid copolymer of the same charge. The former has a more even distribution of groups leading to a greater proportion of the least reactive BAB triad (where A are the acrylamide and B are the acrylic acid moieties). 

Most polymers used in oil field operations and resource recovery are synthetic. The man-made materials in common use are polyO-amidoethylene) ( = polyacrylamide ), poly( 1-amidoethylene-r-( sodium 1-carboxylatoethylene ) ( = partially hydrolyzed polyacrylamide ), poly(l-amidoethylene-r-( sodium 1-(2-methylprop-1N-yl-1-sulfonate)amidoethylene) (AMPS-acrylamide copolymer), and xanthan gum. Xanthan gum is a synthetic because no one finds a pool or river contaminated with Xanthomonas compestris that experiences the right sequence of solute to naturally produce the exocellular gum polymer. A fermenter is a man made object, a tree is not. 

Bakalik and Kowalski investigated the sulfomethylation reaction in some detail using C-13 NMR.9 They found there was no detectable amount of amidomethylsulfonate under the condition described by Schiller and Suen. The major products are partially hydrolyzed poly(acrylamide) and the mono, bis, and tris sulfomethylamines. Since the sulfomethylamines are not titratable by the redox titration, the iodometric titration results are not a good indicator for the formation of amidomethylsulfonate product. 

Poly(vinyl alcohol) is utilized as a component of starch-based adhesives.11121114 Other patents report the use of partially oxidized starch,1115 dextrins,1116 dextrins and urea,1117 borax,1118 boric acid,1119 and vinyl methyl ether-maleic acid copolymers.1120 Other patents indicate the use of poly (vinyl alcohol) with partially hydrolyzed poly(vinyl acetate),1121 nonhy-drolyzed poly(vinyl acetate),1122 and poly(vinyl chloride).1123 A few patents have reported such poly acrylic additives as poly (acrylic acid)1124 and its salts,1125 poly(acrylamide),1126 1127 A-methylacrylamide or poly(A-acryl-amide),1128 and polyethyleneimine.1129 Polystyrene has also been used,1130 as well as more complex copolymers such as a maleic acid monobutyl ester-methyl vinyl ether copolymer, together with dextrin and polyacrylamide),1131 carboxylated ethyl acrylate-styrene zinc salt copolymer,1132 ethylene-methyl acrylate-vinyl acetate copolymer,1133 vinyl acetate-vinyl pyr-rolidone copolymer,1134 and ethylene-vinyl acetate copolymer.1135 Some adhesives are compounded with SBR latex1136 1138 and phenol-formaldehyde resins.1139... 

Most research into the study of dispersion polymerization involves common vinyl monomers such as styrene, (meth)acrylates, and their copolymers with stabilizers like polyvinylpyrrolidone (PVP) [33-40], poly(acrylic acid) (PAA) [18,41],poly(methacrylicacid) [42],or hydroxypropylcellulose (HPC) [43,44] in polar media (usually alcohols). However, dispersion polymerization is also used widely to prepare functional microspheres in different media [45, 46]. Some recent examples of these preparations include the (co-)polymerization of 2-hydroxyethyl methacrylate (HEMA) [47,48],4-vinylpyridine (4VP) [49], glycidyl methacrylate (GMA) [50-53], acrylamide (AAm) [54, 55], chloro-methylstyrene (CMS) [56, 57], vinylpyrrolidone (VPy) [58], Boc-p-amino-styrene (Boc-AMST) [59],andAT-vinylcarbazole (NVC) [60] (Table 1). Dispersion polymerization is usually carried out in organic liquids such as alcohols and cyclohexane, or mixed solvent-nonsolvents such as 2-butanol-toluene, alcohol-toluene, DMF-toluene, DMF-methanol, and ethanol-DMSO. In addition to conventional PVP, PAA, and PHC as dispersant, poly(vinyl methyl ether) (PVME) [54], partially hydrolyzed poly(vinyl alcohol) (hydrolysis=35%) [61], and poly(2-(dimethylamino)ethyl methacrylate-fo-butyl methacrylate)... 

AI or ferrosilicon 14 parts. The thickener could also be guat gum crosslinked with (1-10) 1 blend of a partially hydrolyzed (15— 40%) polyacrylamide and a 9U hy wc acrylamide—Na acrylate copolymer prepd as claimed... 

The UV-active monomers chosen as hydrophobes in this study are shown in Chart I. The saturated analogs to the acrylamides, 1 and 2, were the propionamides, 3 and 4, respectively. These analogs were the corresponding model compounds that represented the chromophoric functionality of the hydrophobe when incorporated into a polymer backbone. The polymer systems chosen for this initial attempt to quantify hydrophobe incorporation were copolymers of the hydrophobes and acrylamide (RAM) and their partially hydrolyzed analogs (HRAM), which are terpolymers of hydrophobe, acrylamide, and acrylate. 

Figure 2. a. The emission wavelength for solutions with constant ANS-copolymer concentrations. The copolymer has a mole ratio of acrylamide-octylacrylamide of98.75 1.25 and has been partially hydrolyzed to 20% sodium acrylate, b. The polarization for the same solutions. 

In partially hydrolyzed (ionic) acrylamide gels, phase transition can also be induced by the application of an electric field [167]. The electric forces on the charged sites of the network produce a stress gradient along the electric field lines in the gel. There exists a critical stress below which the gel is swollen and... 

Immobilization Bv Polymer Binding. A popular approach to small molecule reagent immobilization Is to covalently bind it to a thin polymer film covering the fiber optic end. Hydrogel polymers are preferred for analysis of constituents of aqueous media, and poly-acrylamide (55), poly-vinylalcohol (48), and partially hydrolyzed cellulose acetate (56) films have been described. 

Partially hydrolyzed polyacrylamide (HPAM) is produced by the free radical copolymerization of acrylamide and sodium acrylate. The chemical structure of HPAM is shown in Figure 1, where M denotes K or Na, X and Y are the numbers of carboxylate and amide groups, respectively. A very important parameter which determines the charge density of the polymer chain is the degree of hydrolysis, t, defined as ... 

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