Synthesis And Flocculation Performance Of Hydrophobically Associating Cationic Polyacrylamide

In the decolorization of dye and printing and dyeing wastewater,flocculation and sedimentation is one of the most important research directions at home and abroad.Cationic polyacrylamide is an important organic polymer flocculant,which mainly adsorb particles in water by electric neutralization and adsorption bridging,so that the particles in the system are condensed and flocculated to form flocs to achieve the purpose of settling the floc.Introducing hydrophobic monomers into cationic polyacrylamide can enhance the hydrophobic association ability between polymer chains and the interaction between organic polymers and solid particles,and be more conducive to the flocculation and settlement of solid particles.The Hydrophobically Associating Cationic Polyacrylamide P(AM-DMC-TFEMA)was synthesized by using three fluoroethyl methacrylate(TFEMA)as a hydrophobic monomer,methacryl ethoxy three methyl ammonium chloride(DMC)as cationic monomer and acrylamide(AM)monomer by free radical micellar polymerization;Methyl acryl oxoethyl two methyl benzyl ammonium chloride(DMBAC)was synthesized by substitution reaction with two methylamino ethyl methacrylate(DMAEMA)and benzyl chloride as raw materials;Methyl acryl oxoethyl two methyl benzyl ammonium chloride(DMBAC)was synthesized by substitution reaction with two methylamino ethyl methacrylate(DMAEMA)and benzyl chloride as raw materials.The results of this study are as follows.(1)Synthesis of P(AM-DMC-TFEMA):yield and cationic degree were investigated,the reaction temperature,initiator dosage,monomer concentration,reaction time,dosage of SDS to do single factor experiment and response surface optimization experiment,determine the optimal process parameters.The composition and structure of the products were characterized by IR and NMR.The morphology of P(AM-DMC-TFEMA)water solution was investigated by ESEM,and the properties of the aqueous solution were studied by the measurement of surface tension and apparent viscosity.The flocculation performance of diatomite suspension as simulated wastewater was studied.The effects of cationic monomer DMC dosage,hydrophobic monomer TFEMA content,intrinsic viscosity and polymer dosage on the transmittance of supernatant after flocculation were investigated.The results showed that the highest transmittance of the supernatant was 97.31%when the mass fraction of DMC was 30%,the mass fraction of TFEMA was 15%,and the characteristic viscosity was 627.05mL/g.(2)Synthesis of DMBAC:methyl acryl oxoethyl two methyl benzyl ammonium chloride(DMBAC)was synthesized with DMAEMA and benzyl chloride as raw materials.The effects of four factors such as reaction temperature,amount of solvent,material ratio and reaction time on the yield were investigated.The characteristic absorption peaks of quaternary ammonium groups were found by FTIR and ~1 HNMR tests,indicating the synthesis of DMBAC.The optimum conditions are as follows:the reaction temperature is 30,the amount of solvent is45%,the reaction time is 13h,and the molar ratio is 1:1.The synthesis process is stable,high repeatability,high yield of up to 94.49%,compared with the same type,the yield increased by 3.4%.(3)The synthesis of P(AM-DMBAC-TFEMA):a single factor and response surface optimization experiment was made on the reaction temperature,the amount of initiator,the total mass fraction of the mono body,the reaction time,and the better process parameters were determined.The composition and structure of the product were characterized by IR and 1H-NMR.The morphology of the polymer was observed and analyzed by ESEM,and the microstructure of the polymer was analyzed by fluorescence spectroscopy.The flocculation performance of the simulated wastewater by diatomite suspension was studied.The flocculation properties of P(AM-DMBAC-TFEMA),P(AM-DMC-TFEMA)and P(AM-DMC)were compared,and the flocculation mechanism of the polymer in the flocculation process was preliminarily discussed.The results show that the flocculation performance of P(AM-DMBAC-TFEMA)is better than that of P(AM-DMC-TFEMA)and P(AM-DMC).In the process of flocculation,the electrostatic neutralization,hydrophobic interaction,and adsorption of bridging may be used.The electrostatic neutralization is the main force.(4)The synthesized flocculant product was applied to the anionic dye active red X-ray-3B.By comparing with the same cationic polyacrylamide P(AM-DMC),the decolorization rate of P(AM-DMC-TFEMA)and P(AM-DMBAC-TFEMA)was increased by 6.4%and 9.3%respectively,and the removal rate of COD was increased by 7.4%and 10.3%respectively.Both of them had better decolorization efficiency.The decolorization mechanism of P(AM-DMC-TFEMA)and P(AM-DMBAC-TFEMA)on reactive red red was preliminarily discussed.The results show that the process of decolorization may use hydrophobic interaction and charge neutralization.