Abstract: Copolymer acrylamide/2-acrylamide-2-methyl propylsulfonate was synthesized by using acrylamide (AM) and 2-acrylamide-2-methylpropane sulfonic acid (AMPS) as starting materials,and adopting high/low temperature two-step initiating method,with a complex initiator system which composed of NaHSO₃-K₂S₂O₈ and azo diisobutyl amidine hydrochloride (AIBA).Factors that affect the apparent viscosity of the product,such as mass fraction of reacting monomers,mass fraction of initiator,temperature,pH,ratio of monomers,ratio of initiator et al were studied by single factor experiment and orthogonal designed experiment.The optimal preparation conditions of polymers were screened as:monomer mass fraction,25%;initiator mass fraction,0.015%;initiation temperature,10 ℃;pH,7;m(AM):m(AMPS)=5:1;m(K₂S₂O₈):m(NaHSO₃)=2:1;m(NaHSO₃-K₂S₂O₈):m(AIBA)=1:1;initiating time,1.5 h.Temperature tolerance,salt resistance and thermal stability evaluation experiment results showed that the AM/AMPS copolymer product acts good comprehensive performance.

Key words: copolymer, sulfonation, complex initiator, apparent viscosity, temperature tolerance and salt resistance