Synthesis And Flocculation Property Of Amphoteric Polyacylamide

Amphoteric acrylamide(AmPAM)is a kind of soluble polymer with special molecular structure.Compared with cationic acrylamide and anionic acrylamide,it has advantages of the above mentioned PAM.Additionally, AmPAM has such merits as anti-polyelectrolyte and wide pH range.It can be used in the fields of exploitation of the oil field,wastewater treatment and paper-making.Therefore,it is very necessary to prepare the AmPAM and to conduct its application research for the national economy development and environmental protect.In view of problem of uncompatible between anion and cation in copolymerization reaction,amphoteric polyacrylamide was synthesized with anion polyacrylamide by Mannich reaction and quaternized with dimethyl carbonate.The result shows that as the quaternized reagent,dimethyl carbonate can not only avoid the toxicity of dimethyl sulphate,but also have the best quatemized affect.While the optimize conditions of flocculation results were obtained:the mol ratio between polyacrylamide,form - aldehyde and dimethylamine was 1:1.0～1.2:1.0～1.2;T=40～50℃,t=3～5h and then quaternized by dimethyl carbonate in final.The experiment result show that the value of pH has influence of the best concentration of AmPAM when it is used synthesized AmPAM as the fllocculant,the best mess concentration of AmPAM is 2.5ppm in the case of neutrality and acidity,however,in the case of alkality,it has the increase current.And the rate of sedimentation can be 90%in the scale of pH value 2-12.AmPAM has the better flocculant property and abroad pH adaptability than anion PAM.