Study Of Aqueous Two-phase Copolymerization Method And Application Research Of Cationic Polyacrylamide

Polyacrylamide(PAM)is made up of acrylicamide(AM)and its derivatives of homopolymer and copolymer.It is widely used in water treatment,paper making,petroleum,coal,mining,geological and construction industries and is one of the most important water soluble polymer.AM/DAC is a cationic polyacrylamide(CPAM)copolymer and a linear water soluble polymer with high positive charge density,good water solubility,high intrinsic viscosity,etc.Acrylamide(AM)system of aqueous two-phase polymerization has been researched before,but studies in aqueous two-phase system for acrylamide and cationic monomer copolymerization reaction were rare.Aqueous two-phase copolymerization about cationic monomer and acrylamide is an extension of acrylamide aqueous two-phase polymerization.It introduces cationic monomer,more in line with the requirements of water soluble polymer industrial development,which overcome the common difficulties about aqueous solution polymerization mixing and heat transfer problems,and improve the stability of the system.On the basis of comprehensive literature,this paper use acrylamide(AM)and cationic monomer(acryloyl oxygen ethyl trimethyl ammonium chloride DAC)as reaction monomers,polyethylene glycol(PEG)for split phase medium,ammonium persulfate and sodium bisulfite redox system as initiator,through the synthesis method of the aqueous two-phase copolymerization,compound the stability cationic polyacrylamide P(AM-DAC)copolymer.And by optimize the polymerization process condition,and characterized the relative molecular mass and cationic degree of the product,we got the best product.And we apply the product to simulate wastewater,and measure the product’s flocculating ability by use the removal rate as comparing values.By single factor experiment,we measured the effects about the initiator,monomer concentration,temperature,concentration of monomer ratio and phase medium edc.conditions on the synthesis of system about the copolymer molecular weight of copolymer and cationic degrees.Four factors three levels orthogonal experiment design at the same time.By those experimental,we get the experimental optimum reaction conditions for synthesis of molecular weight of copolymer: the dosage of initiator is 0.2 mL,temperature is 40 ℃,monomer amount is 16%,PEG is 3.5 g and the Polymer relative molecular mass is 11.24 x 105.And the optimum reaction conditions of cationic degrees are as follows: the initiator 0.2 mL,temperature 50 ℃,total monomer 12%,PEG 3.0 g;The optimum reaction conditions for cationic polyacrylamide cationic degree is 28.67%.At the same time,the structure of the polymer was characterized by IR spectrum analysis.The results show that the polymerization product CPAM is really formed by the polymerization of two monomers.We measured the AM and DAC competitive rate by three methods:Fineman-Ross(F-R)method,Kelen-Tudos(K-T)method and Yezrielev-Brokhina-Roskin(Y-B-R)method.Results show that the method of K-T and Y-B-R method measured competitive rate more accurately,AM and DAC competitive rate respectively is r AM = 2.1800,rDAC = 0.28966,two copolymerizations belong to non-ideal co-polymerization.And through the competitive poly rate value,we can calculate the distribution of the sequence length about copolymer and drawing the curve about copolymerization systemat the same time.Make the homemade P(AM-DAC)used to simulate wastewater’s flocculation process about diatomite suspension and use the turbidity rate as the measure index of homemade products flocculation effect,we studied the effect of relative molecular mass and cationic degree on the flocculation effect,and choose a set of better flocculation product as flocculant.By examining the amount of homemade products respectively,pH value,flocculation time,speed value,and settling time on the influence of diatomite suspension about flocculation performance and the analysis of the orthogonal experiment,the result showed that the optimum technological conditions for the flocculant dosage is 5 mL,speed 240 r/min,pH is 6,the mixing time is 15 min.At the same time,under this condition,the CPAM’s removal rate of kaolin suspensions reached 87.5%.