Study On The Properties Of The Compound Solution Formed By Cationic Polyeletrolyte And Anionic Surfactant

In the thesis, a cationic polyelectrolyte was synthesized by means of free radical copolymerization of acrylamide (AM) and cationic mononer named methylacryloyloxyethy trimethylammonium cholride (MC-80) in aqueous solution by using oxidizer-reducer-azocompound as complex initiator. The effects of experimental conditions, including concentration of the monomers, the distribution ratio of monomers, the distribution of the initiators, reaction temperature, etc. on the free radical co-polymerization in aqueous solution were studied. A series of products with the molecular weight between 1.0 X106 and 6.0 X106 and the cationic degree from 1 % to 60 % have been obtained . Based on this, the properties of the mixed solution, which was formed by cationic polyeletrolyte (CPAM)and anionic surfactant sodium dodecylsulfate (SDS), were emphatically and systematically studied. These properties include the compatibility and stability of the CPAM and SDS, the visual viscosity, the conductivity and the rheological behavior of the compound solution and so on.The results of the experiments indicated that the compatibility of SDS and CPAM must be concerned when they are used to obtain their compound solution; and their concentration and chemical computation ratio must be strictly controlled .If the distribution ratio of CPAM and SDS is proper, a more steady compound solution will be obtained. SDS can enhance the viscosity of the polyelectrolyte in a diminutive range of concentration. Because these two molecules have opposite electric charges, they can form polyelectrolyte-surfactant macromolecular complex, which mainly depends on the electrostatic and hydrophobic interaction between these two molecules with opposite electric charges, namely the electric charge degree. It has little to do with the molecular weight of the polyelectrolyte. When the cationic degree of CPAM is less than 12 %, the distribution ratio of SDS and CPAM is far cry from that of equivalent electric degree in theory; when it is more than 20 %, the distribution ratio of SDS and CPAM is equal to that of equivalent electric degree in theory; when the cationic degree is 45% more higher, there will be another kind of deviation that cationic polyelectrolyte with high density charges could accept more equivalent amount of oppositely charged surfactant. The compound solution performs as pseudo-fictile fluid, and its visual viscosity is reduced when the shearing velocity increases. The higher the cationic degree of CPAM, the more apparent the rarefying behavior of the polymer-surfactant complex, but it still is pseudo-fictile fluid. In addition, such factors as the molecular weight of CPAM, temperature and PH value etc, have different effect on the properties of the mixed solution, including its visual viscosity, conductivity, rheological behavior and so on.