Synthesis And Properties Of Novel Cationic Polyacrylamide By Aqueous Solution

The different polymers were synthesized by aqueous copolymerization of acrylamide（AM）,guar gum（GG）and dimethyldiallylammonium chloride（DMDAAC）using complex initiation system at low temperature.The effect of different factors on the molecular weight of polymers were discussed.The flocculation experiments were carried out in industrial wastewater by using polymers.FT-IR,¹H NMR and TGA have been applied to investigate the structures and the stability of the polymers.For this study,the detailed synthetic procedure for the series of polymers was given as follow:The polyacrylamide homopolymer was synthesized by aqueous copolymerization of acrylamide（AM）using complex initiation system at low temperature.Effects of monomer concentration,the amount of azo initiator,initiator concentration,temperature,and time on the molecular weight of polymers were investigated.The results showed that the best conditions were given as follow:the monomer concentration was 30%,the amount of azo initiator was 0.35%,the reaction temperature was 5°C,the reaction time was 70 min.The the molecular weight of polymers can reach 7.41×10⁶ g/mol.FT-IR have been applied to investigate the structures of the polymers.The flocculation experiments were carried out in industrial wastewater by using polyacrylamide homopolymers.The COD and turbidity removal efficiency of polyacrylamide homopolymers could reach 73%and 85%.The P（DMDAAC-AM）was synthesized by aqueous copolymerization of acrylamide（AM）and dimethyldiallylammonium chloride（DMDAAC）using complex initiation system at low temperature.FT-IR,¹H NMR and TGA have been applied to investigate the structures and the stability of the copolymer.Effects of mononer concentration,initiator concentration,temperature,and time on the molecular weight of the P（DMDAAC-AM）were investigated.The results showed that the best conditions were given as follow:the monomer concentration was 30%,W_DMDAAC:W_AM=0.5:1,the initiator concentration was 0.05%,W_K2S2O8:W_NaHSO3=1:0.7,the reaction temperature was 5°C,the reaction time was 60 min.The molecular weight of the P（DMDAAC-AM）can reach 7.23×10⁶ g/mol.The effect of the dosage of flocculantion,pH of solution,types of flocculantion on the COD and turbidity removal efficiency were studied.The results of FT-IR and ¹H NMR indicated that the P（DMDAAC-AM）was synthesized.TGA results showed that the thermal stability of copolymer was good.It was found that the COD and turbidity removal efficiency of the P（DMDAAC-AM）could reach 87%and 91%at the dosage of 40 mg/L.The COD and turbidity removal efficiency of P（DMDAAC-AM）could reach 84%and 89%at pH of 5.The grafting of acrylamide onto guar gum in aqueous solution has been synthesized using ceric-ion-induced redox initiation with raw materials of acrylamide（AM）and guar gum（GG）.Effects of monomer concentration,initiator concentration,temperature,and time on the molecular weight of the P（GG-AM）were investigated.The result shows that the best conditions are given as follow:the monomer concentration was 35%,the initiator concentration was 0.07%,the reaction temperature was 5°C,the reaction time was 110 min.The molecular weight of polymers can reach 7.32×10⁶ g/mol.The effect of the dosage of flocculantion,pH of solution,on the COD and turbidity removal efficiency were studied.TGA result showed that the thermal stability of copolymer was good.It was found that the COD and turbidity removal efficiency of the P（GG-AM）could reach 89%and 93%at the dosage of 40 mg/L.