Preparation And Research Of Water-soluble Anionic Polyelectrolyte And Ampholytic Polyelectrolyte

With the improvement of people’s quality of life, the awareness of environmental protection enhanced. In the treatment of industrial wastewater, it is urgent to prepare polyelectrolyte flocculant with the following advantages:high molecular weight, dissolved rapidly and convenient to use. The traditional flocculant has many disadvantages such as low efficiency、more dosages and high cost. In contrast, the ionic polyelectrolyte flocculant, prepared by the inverse emulsion polymerization, has many advantages such as high efficiency, less dosages and easy to use in treatment of industrial wastewater. In addition to, the polyelectrolyte microgel, obtained by adding cross-linker to the linear polyelectrolyte, can be applied in many fields such as agriculture and forestry, building, biological engineering, drug delivery, petroleum engineering, nanomaterial composites and so on.In the chapter one, the status of studying at home and abroad as well as the application scenarios of polyelectrolyte was summarized.In the chapter two, an anionic polyelectrolyte P(AM-co-AAK) was synthesized by inverse emulsion polymerization, in which acrylamide (AM) and potassium acrylate (AAK) were used as monomers, Span80and OP-10were used as composite emulsifier and potassium persulfate-tetramethylethylenediamine (KPS-TMEDA) was used as redox initiator. The structure and morphology of the product was characterized. Then some factors of impacting the stabilization and intrinsic viscosity of product latex were investigated such as the ratio of reactants, reaction temperature, dosage of initiator and so on. In the end, the salt-resistance of the product was studied. The results show that P(AM-co-AAK) carried the negative charge, and the amount of charge carried under alkaline conditions was higher than that under acidic conditions. Furthermore, the negative charge of the polyelectrolyte salt solution is higher than its aqueous solution. As a result, the product shows salt resistance.In the chapter three, The various influence effects on the flocculation performance of P(AM-co-AAK) were investigated in0.1wt%kaolin suspension simulated wastewaters, including:intrinsic viscosity, product dosage and pH value of system. The results show that the flocculation performance of the product is better than the commercially available polyacrylamide. When intrinsic viscosity is6.6dL/g, the flocculation performance is the best and the best dosage is3mg/L.The flocculation effect in the alkaline condition is better than that in the acid condition.In the chapter four, in the lower temperature(30℃), an anionic polyelectrolyte microgel P(AM-co-MAA) was prepared by inverse suspension polymerization. The structure of P(AM-co-MAA) was characterized by Fourier transform infrared spectroscopy (FT-IR). And their morphologies was characterized by high resolution field emission scanning electron microscope (SEM). Some factors influenced the particle size of polyelectrolyte microgel also were investigated, including the content and neutralization degree of the anionic monomer, the content of the cross-linker. The results show that the higher the content and neutralization degree of the anionic monomer, the smaller particle size of polyelectrolyte microgel. And with increasing the content of cross-linker, the particle size of P(AM-co-MAA) become larger firstly, then become smaller.In the chapter five, an amphoteric polyelectrolyte microgel P(IA-co-AM-co-DM C) was synthesized in organic solvent by two-step precipitation polymerization, in which itaconic acid(IA), acrylamide(AM), methacryloyloxyethyl trimethylammonium chloride(DMC) were used as monomers, N,N’-methylenebisacrylamide(BIS) was used as cross-linker, azobisisobutyronitrile(AIBN) was used as initiator. The structure, morphology and thermal stability of the product were characterized by FTIR, SEM and TG. Furthermore, the pH sensitivity and drug loading efficiency of polyelectrolyte microgel were investigated. The results show that the amphoteric polyelectrolyte microgel P (IA-co-AM-co-DMC) has significant pH sensitivity and better drug loading performance comparing to the cationic polyelectrolyte microgel P(AM-co-DMC). When pH is larger than PI and pH is smaller than PI, the drug loading efficiency of P(IA-co-AM-co-DMC) within10h is almost equal to98%, while pH=PI, the drug loading efficiency of P (IA-co-AM-co-DMC) within10h is only78%, and it need12h to achieve drug loading balance.