Separation acrylamide-acrylic acid

Sakohara S, Sakata T, and Asaeda M. Separation of water-acetone mixtures by acrylamide-acrylic acid copolymer gel prepared in pores of ceramic thin membrane. Kobunshi Ronbunshu. 1989 46(10) 635-638. 

Flocculants cause colloidal clay particles to coagulate thus promoting separation from the drilling fluid which has been circulated down the wellbore and returned to the surface. The treated fluid may then be pumped back down the well bore. Sodium chloride, hydrated lime, gypsum, sodium tetraphosphate, polyacrylamide, poly(acrylamide-co-acrylic acid), cationic polyacrylamides, and poly(ethylene oxide) have been used commercially. 

General. Aqueous solutions of hydrophilic monomers were emulsified in xylene using water-in-oil emulsifiers, and polymerized using oil-soluble initiators. Typical hydrophilic monomers were sodium p-vinylbenzene sulfonate, sodium vinylbenzyl sulfonate, 2-sulfoethyl acrylate, acrylic acid, acrylamide, vinylbenzyl-trimethylammonium chloride, and 2-aminoethyl methacrylate hydrochloride. Typical oil-soluble initiators were benzoyl and lauroyl peroxides. In some cases, water-soluble potassium persulfate was used, both separately and in mixtures with oil-soluble peroxides. Of the water-in-oil emulsifiers, one of the most effective was Span 60 (technical sorbitan monostearate. Atlas Chemical Industries, Inc.). 

Several copolymers of acrylamide are used in practice. The addition of the acrylamide units in a copolymer can modify the polarity and bring a different hydrophilic character to the copolymer. Some pyrolysis studies on acrylamide copolymers are reported in literature [5]. Pyrolysis experiments for two copolymers of acrylamide are discussed below. The first copolymer is poly(acrylamide-co-acrylic acid) 1.5 wt % acrylic acid, CAS 9003-06-9, with M = 15,000,000. The pyrogram of this compound is shown in Figure 6.7.21. The pyrolysis was done at 600° C in He at a heating rate of 20° C/ms. The separation was done on a Carbowax column in similar conditions as for other experiments (see also Table 4.2.2). 

Figure 6.7.21. Result for a Py-GC/MS analysis of poly(acrylamide-co-acrylic acid) 1.5 wt % acrylic acid CAS 9003-06-9, with M = 15,000,000. Pyrolysis done on 0.4 mg material at 60(f C in He, with the separation on a Carbowax type column.

CTMA Acrylamide/JV,J T -methylenebisacryl-amide, carboxyethyl acrylate, acrylic acid, Hexagonal No phase transition Macroporous layer-like morphology Phase separation between template and polymer [52]... 

Reactives of Side-Chains of Monocyclic Thiophens. - The rate constants for the esterification of some 3-, 4-, and 5-substituted thiophen-2-carboxylic acids and of some 2- and 4-substituted thiophen-3-carboxylic acids with diazodiphenylmethane in methanol solution have been measured, and linear correlations gave information about the transmission of substituent effects. The rates of alkaline hydrolysis of ethyl thiophen-2-carboxylate in ethanol-water and DMSO-water media have been measured and compared with those of other heterocyclic esters. The kinetics of iodination of 2-acetylthiophen in methanol-water, using different carboxylate buffers, have been studied.Basicity constants have been measured for j3-(2-thienyl)-acrylamides and compared with those of the corresponding benzene and furan derivatives. The acidity constants of ( )-a-phenyl-j3-(2-thienyl)-acrylic acids and analogous furan-, selenophen-, and pyridine-substituted compounds have been measured, and have been rationalized by an equation involving separate contributions of polar, conjugative, and steric effects of the heterocycles. ... 

Finally, we note that not all aqueous polymer solutions exhibit the foregoing behaviour. Thus, for example, poly(acrylic acid) and poly(acry-lamide) at low pH display positive values for the enthalpy and entropy of dilution parameters (Silberberg et ai, 1957). Day and Robb (1981) have confirmed calorimetrically that the heat of dilution of poly(acrylamide) in water is endothermic, althou, in contrast, they found that the substituted polyacrylamides poly(N-methyl acrylamide) and poly(N,N-dimethyl acrylamide) displayed negative heats of dilution. It was proposed that the endothermic character of the poly(acrylamide) solutions was a consequence of the energy required to separate the associated amide dipoles. 

Insoluble polychelates separate when an aqueous solution of poly(acrylic acid-co-acrylamide) is added to an aqueous solution of Cu(II), Co(II) and Ni(II) [30]. Tetrahedral arrangements were found for Co(II) and Ni(II). But homogeneous complex solutions can also be obtained as was shown by controlling the composition of an inter-polyelectrolyte of poly(acrylamide-co-acrylic acid) and poly(acrylamide-co-dimethyldiallylammonium chloride) with... 

The use of acrylic acid not only led to a functionalization of nanoparticles, but also was important as a structure-directing monomer for the formation of nanocapsules. In this case, the hydrophilic groups of the acrylic acid [30] or methacrylic acid [31] resulted in the formation of a nanocapsule structure, instead of Janus-like or even separate nanoparticles. The copolymerization of the functional n-methylol acrylamide with vinyl acetate was found to follow (in batch miniemulsion) the Mayo-Lewis equation, despite huge differences in the solubility of the monomers in the aqueous continuous phase [32]. A functionality of fluori-nated particles could be easily introduced by copolymerizing fluoroalkylacrylates with protonated monomers, such as acrylic acid and methacryloxyethyltrimethyl ammonium chloride [33]. 

The mixture of the PAS and PEG aqueous solutions thus lost mutual solubility at more than given concentration and phased into two layers. Observation of a similar phenomenon was reported by Higashi ), et al., on a combination of poly (vinyl alcohol)/poly (ethylene oxide), poly (acrylamide)/poly (ethylene oxide), or poly (acrylamide)/ poly (acrylic acid) and so on. The aqueous solution of a combination of poly (2-vinylpyridinium chloride) and poly (ethylene oxide) was studied by M.M, Mario, et, al, and they made public a phase separation diagram of this system, which resembles the PAS/PEG system. The phase separation of the combination of two water soluble pol3nner mixtures was due to the result of the lost mutual solubility, and not of the formation of a polymer-pol3nner complex 3)4) such as poly (acrylic acid) and poly (ethylene oxide). 

The hydrolysis must be carefully carried out, since if taken too far, acrylic acid is produced. In one procedure, the acrylonitrile is dissolved in concentrated sulphuric acid and then the solution is poured into cold water this yields acrylamide sulphate. Treatment with alkali gives acrylamide which is separated by crystallization. Acrylamide is a white crystalline solid, m.p. 84-85°C. 

On the other hand, several polymers of acrylic acid (55), acrylamide (56), and (meth)acrylate with sulfobetain (57) or uracil side group (58) which undergo UCST (not LCST) phase separation, have been studied [209-214], as... 

Another successful example is the separation of a series of steroids listed in Fig. 6.11 using a monolithic capillary column prepared by redox initiated polymerization of a solution of acrylamide 4, methylene bisacrylamide 5, vinylsulfonic acid 12, and dodecyl acrylate 18 in N-methylformamide/TRIS-boric acid buffer (pH 8.2) to which polyethylene glycol) (MW 10,000) was added (overall composition 5% T, 60% C, 10% vinylsulfonic acid, 15% lauryl acrylate, 3% polyethylene glycol)). The capillary tube was first vinylized and its part beyond the detection window was coated with linear polyacrylamide to avoid band broadening. Since laser induced fluorescence was used to decrease the detection limit of the method to about 100 attomoles for neutral steroids, all of the analytes were first tagged with dansylhydrazine. Fig. 6.12 shows an... 

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