Preparation Of Amphoteric Lonic Polyacrylamide Assisted By Photo-initiation

Amphoteric polyacrylamide of different cationic monomer was synthesized inphoto-assisted solution polymerization by using acrylamide (AM) and acrylic acid(AA) as materials, they reacted respectively to three kinds of cationic monomer(methacryloyloxyethyl trimethyl ammonium chloride (DMC), acryloyloxyethyl threemethyl chloride (DAC), diallyl dimethyl ammonium chloride (DMDAAC)). Thestructure of the product was characterized using FT-IR technology, flocculation wasevaluated by sludge dewatering degree of flocculation.The factors on the intrinsic viscosity of the polymer and dissolution time such asthe initiator mode, initiator system, the total mass fraction of initiator, the initiatortemperature, monomer concentration, pH, w(oxidizer):w(reductant), redoxconcentration, the mass fraction of azo initiators, the mass fraction of cosolvent andcomplexing agents etc were investigated. Compared to the traditional initiators, theflocculation performance was measured by altering the intrinsic viscosity of thepolymer, the amount and the content of ionic groups.The obtained optimum conditions for synthesis of P(AM-DMC-AANa)wereinitiation system VA-044,(NH4)2S2O8, NaHSO3, DMAEMA, initiator concentration0.0180%, initiation temperature40℃, monomer concentration40%, pH=6,EDTA·2Na amount0.0020%, the concentration of solubilizing agent0.60%,azo-compound concentration0.0120%, oxidant–reductant concentration0.0060%,mass ratio of oxidizer to reductant1:2, m(DMAEMA):m(NaHSO3)=3:5,m(DMC+AANa):m(AM)=45:55、m(DMC)：m(AANa)=1:1. Under above conditions,the intrinsic viscosity of P(AM-DMC-AANa) was9.72dL·g-1and the dissolving timewas98min. The obtained optimum flocculating conditions were the conditions of thedosage of P(AM-DMC-AANa)0.0250%, intrinsic viscosity9.72dL·g-1, ionic degree35%, the transmittance of treated waster, the flocculating rate and dewatering rate were90.25%,80.76%and88.63%respectively.The obtained optimum conditions for synthesis of P(AM-DAC-AANa)werem(DAC+AANa):m(AM)=15:85, m(DAC)：m (AANa)=2:1, initiation system VA-044,(NH4)2S2O8, NaHSO3, DMAEMA, initiation temperature20℃, pH=6,monomerconcentration32%, the concentration of solubilizing agent0.60%, EDTA·2Na amount0.0020%, nitrogen of30min, azo-compound concentration0.0100%,oxidant–reductant concentration0.0060%~0.0080%. Under above conditions, theintrinsic viscosity of P(AM-DAC-AANa) was13.56dL·g-1and the dissolving timewas66min. The obtained optimum flocculating conditions were the conditions of thedosage of P(AM-DMC-AANa)0.0250%, intrinsic viscosity12.13dL·g-1, ionic degree25%, m(DAC):m(AANa)=1:2, the transmittance of treated waster, the flocculatingrate and dewatering rate were93.90%,84.47%and92.41%respectively.The obtained optimum conditions for synthesis of P(AM-DMDAAC-AANa)were initiation system VA-044,(NH4)2S2O8, NaHSO3, DMAEMA,m(DMDAAC+AANa):m(AM)=30:70, n(DAC):n(AANa)=1:2.5, initiationtemperature25℃, monomer concentration30%, pH=6, the concentration ofsolubilizing agent0.80%, EDTA·2Na amount0.0020%, azo-compound concentration0.0120%, w((NH4)2S2O8)=0.00175%, w(NaHSO3)=0.0025%, w(DMAEMA)=0.0020%. Under above conditions, the intrinsic viscosity of P(AM-DMDAAC-AANa)was12.87dL·g-1and the dissolving time was93min. The obtained optimumflocculating conditions were the conditions of the dosage of P(AM-DMC-AANa)0.03%, dissolved salt concentration1.0%, intrinsic viscosity11.35dL·g-1, ionic degree30%, flocculation achieved best.