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Polyacrylamide The Physical And Chemical Properties
Sep 27, 2017

Classification of polyacrylamide polyacrylamide products introduction: polyacrylamide (PAM) is a water-soluble polymer, insoluble in most organic solvents, has good flocculation sex, can reduce the friction resistance between liquid, by ion characteristic points can be divided into non-ionic and anionic, cationic and amphoteric four types. (note: polyacrylamide is different from acrylamide)

The physical and chemical properties

PAM PAM consists of acrylamide (AM) monomers by free radical polymerization of water soluble linear polymers, has good flocculation sex, can reduce the friction resistance between liquid, by ion characteristic points can be divided into non-ionic and anionic, cationic and amphoteric four types. Polyacrylamide (PAM) does not dissolve in most organic solvents, such as methanol, ethanol, acetone, ethyl ether, fatty hydrocarbon and aromatic hydrocarbon, except a few polar organic solvents, such as acetic acid, acrylic acid, chloroacetic acid, ethylene glycol, oil, melting urea and formamide. But these organic solvents have limited solubility and often need to be heated, otherwise there is no application value.

At the appropriate low concentration, polyacrylamide solution can be regarded as the network structure, and the entanglement and hydrogen bonding of the interchain machinery form a network node. When the concentration is high, the solution is gelatinous because the solution contains many chain contact points. PAM aqueous solution with a lot of energy and water mutually soluble organic matter has good compatibility, has good compatibility to the electrolyte, the ammonium chloride, calcium sulfate, copper sulfate, potassium hydroxide, sodium carbonate, sodium borate, sodium nitrate, sodium phosphate, sodium sulfate, zinc chloride and boric acid, and phosphoric acid substances such as insensitive.

Polyacrylamide mesh: the mesh refers to the granularity of the material or thickness, item number is the number of squares on the per unit area. General definition refers to the 1 inch by 1 inch area has how many mesh count, the number of mesh screen. Such as 600 mesh is 600 per square inch square mesh, mesh of polyacrylamide 20 mesh to 80 mesh, which is between 0.85 mm to 0.2 mm, this is granular polyacrylamide mesh size, powdered polyacrylamide mesh size can be controlled at about 100 mesh, mesh of polyacrylamide is more easily dissolved, the greater the polyacrylamide mesh size alone is unable to measure the quality of the product!

Polyacrylamide is white powder or granules, density of 1.32 g/cm3 (23 degrees), glass transition temperature is 188 degrees, the softening temperature to 210 degrees, a general method contains a small amount of water when dry, dries quickly again suck up moisture from the environment, with the separation of freeze drying homopolymer is white fluffy non-crystalline solid, but when after precipitated from the solution and dry is vitreous partially transparent solid, completely dry PAM PAM is brittle solid white, dry goods polyacrylamide is usually under the condition of moderate dry, average moisture content is 5% ~ 15%, casting preparation of polymer film on glass, are transparent, hard, brittle solid,

considerations

Precautions for the use of cationic polyacrylamide:

1. The size of the flocculation: the flocculation is too small to affect the speed of drainage. The flocculation is too general to make the flocculation more water and reduce the mud biscuit degree. The molecular weight of polyacrylamide was selected to adjust the size of the flocculation.

2. Sludge characteristics: the first understanding of the source, characteristics and composition of the sludge is the proportion of the sludge. Depending on the nature of the sludge, sludge can be divided into organic and inorganic sludge. Cationic polyacrylamide used for disposal of organic sludge, relative anionic polyacrylamide flocculant used in sludge, inorganic alkali is very strong in the anionic polyacrylamide, and should not be used when strong acid anionic polyacrylamide, high solid content in sludge usually polyacrylamide dosage is large.

3. Flocculation strength: the flocculation should be stable and not broken under the shear action. The progression-polyacrylamide molecular weight or the selection of suitable molecular structure can help to improve the stability of the flocculation.

Ion degrees: 4, polyacrylamide for dewatering sludge, different ion flocculant are available after pick to do first test, select the best suitable polyacrylamide, which can achieve the best effect of flocculant, and can make the dosage, at least, to save money.

5. Dissolution of polyacrylamide: a good solubility for flocculation. The concentration of polyacrylamide solution can be considered when the speed of dissolution is sometimes accelerated.