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The polymerization reaction creates a gel because of the added bisacrylamide, which can form cross-links between two acrylamide molecules. The ratio of bisacrylamide to acrylamide can be varied for special purposes, but is generally about 1 part in 35. The acrylamide concentration of the gel can also be varied, generally in the range from 5% to ...
Acrylamide reacts with an aqueous solution of formaldehyde in the presence of copper(I) chloride as a polymerization inhibitor and sulfuric acid as catalyst to form N,N′-methylenebisacrylamide with yields of 60 to 80%.
Acrylamide (or acrylic amide) is an organic compound with the chemical formula CH 2 =CHC(O)NH 2.It is a white odorless solid, soluble in water and several organic solvents. From the chemistry perspective, acrylamide is a vinyl-substituted primary amide (CONH 2).
Polyacrylamide is of low toxicity but its precursor acrylamide is a neurotoxin and carcinogen. [1] Thus, concerns naturally center on the possibility that polyacrylamide is contaminated with acrylamide. [12] [13] Considerable effort is made to scavenge traces of acrylamide from the polymer intended for use near food. [1]
Solution-based polymerization is commonly used today for SAP manufacture of co-polymers, particularly those with the toxic acrylamide monomer. This process is efficient and generally has a lower capital cost base. The solution process uses a water-based monomer solution to produce a mass of reactant polymerized gel.
The synthesis of poly(N-isopropylacrylamide) began with the synthesis of the acrylamide monomer by Sprecht in 1956. [13] In 1957, Shearer patented the first application for what would be later identified as PNIPA for the use as a rodent repellent. [14] Early work was piqued by theoretical curiosity of the material properties of PNIPA.
The polymerization is obtained with a broad molecular weight distribution due to the high viscosity and lack of good heat transfer. very high molecular weights are obtained. Gel effect. For reducing the disadvantages of bulk polymerization, the process can be carried out in a solution. This is known as solution polymerization. [2]
Copolymerization of trimethylammoniumethyl acrylate chloride with acrylamide leads to high molecular weight cationic polyacrylamides, which are widely used as coagulants and flocculants [11] in waste water purification and as retention and dewatering agents in papermaking.