Preparation Of PAM And P(AM-DMDAAC) By Inverse Microemulsion Polymerization And The Study On Polymers Flocculation Property

On the basis of the analysis of the existent polymer flocculation aids and a lot of experimental studies, the non-ionic PAM and the cationic copolymer of acrylamide(AM)and Dimethyldiallylammonium chloride(DMDAAC)have been synthesized respectively by the inverse microemulsion polymerization.The favorable system liquid paraffine/ Span80-Tween60 was selected as oil phase and eumulsifiers according to the study on the solubility of water phase in oil phase. By the HLB value, the phase volume and the electrical conductivity methods, the effects of NaAc, comonomer composition and comonomer concentration on the form and stability of the microemulsion system have been studied by the numbers, then, not only the best Emin and the best HLBopt of the microemulsion system formation have been gotten, but also the microemulsion systems have been investigated and optimized. The results showed that the minimum emulsifier concentration (Emin) was only about 9% and the monomers content reached more than 25% for the optimized microemulsion system. The monomers and NaAc with salting-out electrolyte could conduce to optimize microemulsion system, enhance its stability, increase the solid content and reduce the lowest emulsifiers content.By the inverse microemulsion polymerization,(NH4)2S2O8-Na2SO3 as initiators,with the polymerization systems of the liquid paraffine/Span80-Tween60/AM-H2O-NaAc or the liquid paraffine/Span80-Tween60/AM- DMDAAC-H2O-NaAc, non-ionic PAM and the cationic copolymer P(AM-DMDAAC) have been synthesized respectively. The effects of various polymerization factors on the intrinsic viscosity, the yield and cationic degree, such as mass fraction of monomer, mass fraction of initiator, mass fraction of emulsifiers, mass ratio oil to water, temperature and so on. The best polymerization condition of PAM could be obtained with the condition of the mass ratio initiators to monomer w=0.5%～0.6%, the mass ratio emulsifiers to oil w=20%～23.1%, and the mass ratio oil to water =2.0～2.5. The best polymerization condition of P(AM-DMDAAC) could be obtained with the condition of w(initiators)=0.6%, the mol ratio of (NH4)2S2O8 to Na2SO3=0.8, w(monomers)=53.1%,the ratio emulsifiers to system=9.1%, the mass ratio oil to water =1.67, the polymerization temperature ranging from 30℃to 40℃, w (NaAc)<4%, w(complexant)= 0.17%. P(AM-DADMAC) could be gotten with the intrinsic viscosity of 1812.4 ml·g-1 and the cationic degree of 29%(weight) when the mass ratio oil to water =1.67. The results also showed that the copolymer contains the chain unit of AM and DMDAAC, and the ratio of each monomer unit is close to those enriched in the inverse microemulsion copolymerization system.PAM and P(AM-DADMAC) were applied to treat kaolinite suspension, coal slurry suspension, paper making waste water by the beaker tests and the measuring cylinder tests, so as to study the flocculation effects of PAM with various intrinsic viscosity and P(AM-DMDAAC) with the various intrinsic viscosity or the various the cationic degree. The experimental results showed that P(AM-DADMAC) and PAM synthesized by the inverse microemulsion polymerization had the better flocculation property than the other flocculants, and the flocculation property of P(AM-DADMAC) was optimal.