Methylene bisacrylamide

Bis-acrylamide (Af,Af -methylene bisacrylamide) [110-26-9] M 154.2, m >300 . Recrystd from MeOH (lOOg dissolved in 500mL boiling MeOH) and filtered without suction in a warmed funnel. Allowed to stand at room temperature and then at -15°C overnight. Crystals collected with suction in a cooled funnel and washed with cold MeOH). Crystals air-dried in a warm oven. TOXIC. 

The performance of several Sephacryl gel combinations is illustrated by results achieved for glucans from different types of starch granules. The applied Sephacryl gels of Pharmacia Biotech (15) are cross-linked copolymers of allyl dextran and N,N -methylene bisacrylamide. The hydrophilic matrix minimizes nonspecific adsorption and thus guarantees maximum recovery. Depending on the pore size of the beads, ranging between 25 and 75 im in diameter, aqueous dissolved biopolymers up to particle diameters of 400 nm can be handled. 

TABLE 16.3 Producers (Pharmacia Biotech) Specification of Fractionation Ranges of Cross-Linked Allyl Dextran/N,N -Methylene Bisacrylamide Copolymer-Based Sephacryl Gels for Dextrans... 

For this reaction, soluble monomers are needed, e.g. a mixture of N AT-methylene bisacrylamide as crosslinker, methacrylamide as an inert comonomer, methacrylic acid as ionic comonomer for stabilization [309] and methacryl ami-do-AT-acetaldehyde-dimethylacetal as functional comonomer. The coupling with proteins is only possible if the free aldehyde groups are accessible, i.e. if they are not located in the interior of the microgel. This condition can only be fulfilled by a careful choice of the comonomer composition in the reaction mixture [291]. 

The gel composition is often described by the terms %T and %C. %T refers to the total content of acrylamide (sum of acrylamide and cross-linking monomer), whereas %C is the part of cross-linking substance (e.g., N,N -methylene bisacrylamide) of monomers. 

Before pouring the gel, solution A is made by dissolving 1 mg of ammonium persulfate in 1 ml Soln. A. Solution B is also made freshly by dissolving of 4.114 g urea and 0.125 g N,N -methylene bisacrylamide in 10 ml of Soln. B (do not heat above 30 °C). 

The hemocompatibility of poly(amido-amine) polyelectrolyte complexes was recently studied by Xi, Zhang and coworkers [499, 500]. The poly(amido-amine) was based on piperazine and methylene bisacrylamide, and the polyelectrolyte complexes were obtained from the reaction of poly(amido-amine) with alginic acid, carboxymethyl cellulose or poly(methacrylic acid). Complexes of polyamido-amine and alginic acid with a 1 2 ratio gave the best hemocompatibility. Finally, the blood compatibility of polyelectrolyte complexes based on anionic and cationic cellulose derivatives were studied by Ito et al. [338], In vivo, good blood compatibility of complexes formed from quaternary hy-droxyethyl cellulose reacted with carboxymethyl cellulose and cellulose sulfate was observed. 

The mechanical properties of these membranes were improved by including a crosslinker, methylene bisacrylamide, in the aqueous phase, and by using a styrene/butyl acrylate (BA) mixture as the continuous phase [185]. The styrene/BA mixture had to be prepolymerised to low conversion to allow HIPE formation. The permeation rate of the membrane was improved by including a porogen (hexane) in the organic phase, generating a permanent porous structure [186]. The pervaporation rate was indeed increased, however a drop in selectivity for water from water/ethanol mixtures was also observed. 

The gel was prepared by mixing 66 ml of gel buffer (0.01 M Cd(C104)2, 0.01 M sodium polyphosphate, pH 11) 7.4 ml acrylamide solution (44.4 g of acrylamide, 1.2 g of methylene-bisacrylamide in 100 ml water) and 62.4 ml water in round bottom flask and deaerated for 5 min with a water pump. Then 1.2 ml of freshly prepared ammonium persulfate solution (150 mg in 10 ml water) and 0.1 ml of N,N,N, N tetramethylethylenediamine (TEMED) were added and mixed carefully to avoid the introduction of air. Finally, 100 ml of the resulting solution was poured carefully, to minimize the introduction of air, into a 25 mm-diameter tube. The monomer solution was overlayered with water to remove the meniscus and reduce the entry of air. The polymerization was allowed to proceed overnight at room temperature. The resulting gel, having a polymer concentration of 2.5% and a cross-link density of 2.6%, was used in a home made apparatus. ... 

Glyoxalated copolymers consisting of acrylamide and diallyldimethylammo-nium chloride crosslinked with NJf -methylene bisacrylamide, (I), were prepared by Hagiopol et al. (4) and used as paper-strengthening agents. 

AA BAA CMC CPB CTAB DM SO IPC MVPQ PAA PDADMAB PEG PIPAA SDS SMA TEMED acrylamide methylene bisacrylamide critical micelle concentration cetylpyridinium bromide cetyltrimethylammonium bromide dimethylsulfoxide interpolymer complex methylvinylpiridine units quaternized by dimethyl sulfate poly(acrylamide) poly(diallyldimethylammonium bromide) polyethylene glycol) poly(isopropylacrylamide) sodium dodecyl sulfate sodium methacrylate tetramethylethylenediamine... 

A. 30% acrylamide plus 0.8% methylene bisacrylamide in potassium phosphate buffer... 

Entrapment of enzyme molecule ( y) cross-linked polyacrylamide I prepared by mixing enzyme h acrylamide, methylene bisacrylamide, and catalyst... 

See Problem 1 Increase the percent of cross-linking agent, methylene bisacrylamide, in the gel. 

A means to avoid such tedious optimization can be envisaged by employing stoichiometric monomers to develop strong interactions with the template as mentioned above. The other way is to incorporate hydrophilic comonomers (2-hydroxyethyl methacrylate (HEMA), acrylamide) or cross-linkers (pentaerythri-toltriacrylate, methylene bisacrylamide) in the polymer. This results in an increase of the hydrophilicity of the polymer. Indeed, the use of HEMA for a MIP directed towards the anesthetic bupivacaine resulted in high imprinting factors due to reduced non-specific hydrophobic adsorption in aqueous buffer. This was not the case when HEMA was omitted from the polymerization mixture [27]. These conditions were exploited for the direct and selective extraction of bupivacaine from blood plasma samples. 

Polyacrylamide is a cross-linked polymer of acrylamide. These gels are more difficult to prepare than agarose. Monomeric acrylamide (which is a known neurotoxin) is polymerized in the presence of free radicals to form polyacrylamide. The free radicals are provided by ammonium persulfate and stabilized by TEMED (/V/V/V/V -tetramethylethylenediamine). The chains of polyacrylamide are cross-linked by the addition of methylene-bisacrylamide to form a gel whose porosity is determined by the length of chains and the degree of cross-linking. The chain length is proportional to the acrylamide concentration usually between 3.5 and 20%. Cross-linking bis-acrylamide is usually added at the ratio 2 g bis/38 g acrylamide. 

Fig. 6.2. Electrochromatographic separation of benzyl alcohol (1), resorcinol (2), methylparaben (3), and p-naphthol (4) using a soft gel column (Reprinted with permission from [27], Copyright 1998 Wiley-VCH). Conditions Column 48.5 cm (24 cm active) x 75 pm i.d., stationary phase 4.1% T, 9.7% C, 0.7% S poly(2-acrylamido-2-methyl-l-propanesulfonic acid-co-N-isopropyl acrylamide-co-methylene bisacrylamide) mobile phase 20 80 acetonitrile and 2.5 mol/L phosphate buffer pH 6.8 16 kV.

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