Papers by Keyword: Cationic Polyacrylamide

Abstract: In order to improve the aqueous solutions viscosity and flocculation performance of cationic polyacrylamide, organic montmorillonite was added into polymerization system of polyacrylamide, the cationic polyacrylamide/dimethyl diallyl ammonium chloride/organic montmorillonite (CPAM/DMDAAC/MMT) nanocomposite was prepared by aqueous two-phase polymerization method. The influence of organic montmorillonite content, cationic monomer content, polyethylene glycol concentration, monomer concentration on the intrinsic viscosity of the CPAM/DMDAAC/MMT nanocomposite were discussed. The reaction conditions were optimized by orthogonal test. The chemical component and organic montmorillonite shape of the cationic CPAM/DMDAAC/MMT nanocomposite were analyzed by FTIR and XRD respectively. The results show that CPAM/DMDAAC/MMT nanocomposite with high aqueous solutions viscosity and beyond compare flocculation performance has been obtained by aqueous two-phase polymerization method. The CPAM/DMDAAC/MMT nanocomposite has been used very well as a flocculating agent.

Abstract: A cationic polyacrylamide flocculant (CPAM) for the coal slurry wastewater, was firstly synthesized using acrylamide and cationic monomer ethylene methyl propenoyl trimethylammonium chloride (DMC). The structure of the synthesized CPAM was characterized by means of FT-IR measurement, and the effects of various factors on flocculation performance were studied. The optimum flocculation can be achieved according to the dosage of flocculant between 2 and 5 mg/L, pH value of 6, temperature of 40°C, and the dosage of DMC in CPAM of 17.5%.

Abstract: Cationic polyacrylamides modified with fluorinated methacrylate (FPAM) were prepared with acrylamide, dodecafluoroheptyl methacrylate (DFM) and methacryloxyethyl trimethylammonium chloride by free radical micellar copolymerization. The solution properties of FPAM were investigated. The results show that there are strong hydrophobic associations in the FPAM aqueous solution. The intrinsic viscosity decreases and Huggins constant increases with the increase of DFM content. The apparent viscosity of FPAM solution increases with increasing the FPAM concentration both in water and salt solution. There are maximum values of the apparent viscosity of FPAM with addition of sodium chloride, CTAB and sodium dodecyl sulfate (SDS), respectively. Additionally, the FPAM has higher surface activity in salt solution than in water.

Abstract: A cationic polyacrylamide-grafted starch (St-g-CPAM) flocculant for the coal slurry wastewater, was prepared by using corn starch and acrylamide (AM) as monomers, ethylene methyl propenoyl trimethylammonium chloride (DMC) as cationic monomer through solution polymerization. The effects of initiator concentration, reaction temperature, and monomer concentration on percentage of grafting and the grafting efficiency were investigated. The results show that the optimal conditions of the polymerization are as follows: the monomer to substrate ratio of 2.5, AM:DMC ratio of 2:1, potassium persulfate of 3×10-3 mol/L, reaction time of 4h, the reaction temperature of 50°C. The additional dosage of St-g-CPAM is varying between 20 and 30 mg/L to obtain good flocculation capability

Abstract: Tailings dewatering is an important part of the tailings disposal. Sludge dehydrant is a kind of important auxiliary agent in improving the tailings dehydration dehydrated efficiency in tailings enrichment dehydration. The paper reviews that the preparation and application of special flocculant of specialized flocculants for tailings water treatment. And it points out the development tendency of the specialized flocculants for tailings water treatment. Cationic polyacrylamide as one of dewatering agents is a suitable mean to solve tailings dewatering problem.

Abstract: The effects of concentration of cationic polyacrylamide and pH-value on the migration rate of suspended particles have been measured by a Turbiscan Lab dispersion stability analyzer. The results showed that the migration rate of the suspended particles increases with the increase of concentration of cationic polyacrylamide between 40 and 70mg/L and decreases with the increase of its concentration between 70 and 90mg/L. The migration rate of suspended particles decreases with increasing pH-value or settling time.

Abstract: In the flocculation treatment of oilfield sewage, cationic polyacrylamide (CPAM), which was synthesized by the copolymerization of dimethyldiallylammonium chloride (DMDAAC), acrylamide(AM), and acrylic acid(AA), will react with the residue of oil displacement agent, causing the quick crimp of its linear-molecular-structure chain and deteriorating the flocculating effects. In order to solve the problem, cationic polyacrylamide (CPAM) was grafted by a cationic-terminated spheroidal-molecular-structure hyperbranched polymer (CHP), which was synthesized by introducing methacryloxyethyl trimethylammonium chloride (DMC) into a kind of amino-terminated hyperbranched polymer. Both CPAM and grafted CPAM were used in flocculation treatment of simulated ASP oilfield sewage. The comparison results in flocculating effects indicated that the flocculating effect of grafted CPAM is greater than CPAM, its optimal dosage is 12.5mg/L, and its transmittance of the treated sewage reached 98.6%.

Abstract: The glyoxalted polyacrylamide(GPAM) resins were obtained by cross-linking reaction between glyoxal and cationic polyacrylamide(CPAM) through aqueous solution copolymerization. The based CPAM was synthesized with acrylamide(AM) and diallyl dimethyl ammonium chloride(DADMAC) as raw materials by living free radical solution polymerization. Various synthesis conditions were discussed and the optimum conditions for copolymer’s synthesis were as follows: the amount of DADMAC 20%(wt), the charge of the initiator 0.5%(wt), the dosage of chain transfer agent(2-mercaptoethanol) 1.0%(wt), and the charge of crosslinking monomer 9.0%, the dosage of glyoxal 25%(wt), the pH value of the tertiary reaction 7.5-8.0 and the tertiary temperature about 65°C. The structure of the resulting product was characterized by FT-IR, ¹H-NMR. Then the GPAM resins were used in the process of paper-making as wet-end additive, the results showed that the paper sheets can get a significant increase in strength properties from the added novel product.

Abstract: A new inorganic-organic composite dual-coagulant (PAFC-CPAM) was prepared by polyaluminum ferric chloride (PAFC) and cationic polyacrylamide (CPAM) and its treatment efficiency for oily wastewater was evaluated by coagulation jar tests. PAFC-CPAM dual-coagulants were characterized by FT-infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The FTIR spectra illustrated that there were some chemical reactions between PAFC and CPAM in PAFC-CPAM. SEM micrographs testified that PAFC-CPAM formed compact net structure which is different from PAFC and CPAM, resulting to its outstanding coagulation performance other than monomeric coagulant in treating oily wastewater. Coagulation jar tests presented that PAFC-CPAM improved 1.14% and 0.38% of oil removal rate and reduced 0.35NTU and 0.06NTU of residual turbidity than PAFC and CPAM respectively at the optimal dosage of 120mg/L. PAFC-CPAM enhanced 4.56% and 2.12% of oil removal efficiency and decreased 0.27NTU and 0.01NTU of residual turbidity on average in comparison with PAFC and CPAM respectively in the pH range of 4.0-8.0. All of above-mentioned experiment results demonstrated that PAFC-CPAM behaved superior coagulation performance than PAFC and CPAM.