| In order to obtain hydrophobically associating water-soluble polymers with better properties of salt-tolerance and high temperature-tolerance compared to hydrophobically associating water-soluble polymers originated from acrylamide, a new series of hydrophobically associating water-soluble polymers were synthesized by free radical polymerization with N-vinyl pyrrolidone as hydrophobic monomer and acrylic ester as hydrophobic monomer. The molecular structures of the synthesized acrylic ester and hydrophobically associating water-soluble polymers were characterized by using FRIR and Elemental analysis. The properties under rising temperature were recorded by TG. The aqueous properties were investigated as a function of hydrophobic monomer type, the length of hydrophobic blocks, the ratios of hydrophobic monomer and hydrophobic monomer, salinity and surfactant. Based on the above investigation results, the following conclusions can be drawn:1. The optimized reaction condition for synthesis of acrylic esterThe molar ratio of acrylic acid and alcohol was 1.2∶ 1.0, the mass percents of catalyst and inhibitor were 1.0% and 0.7% respectively, the reaction temperature was below 130°C, the reaction time was 8h, the yield was 97% or so.2. The optimized reaction condition for synthesis of hydrophobically associatingwater-soluble polymersThe initiator concentration was 0.3%, the reaction temperature was 50℃, the monomer concentration was 15%, the reaction time was 6h.3. The effect of hydrophobic blocks length on the solution properties of hydrophobically associating water-soluble polymersThe length of hydrophobic blocks has a strong impact on the aqueous properties of synthesized hydrophobically associating water-soluble polymers. The longer the length ofhydrophobic blocks, the stronger the hydrophobic interactions. Incorporation of hydrophobic blocks with the length higher than 16 cause a dramatic enhancement in viscosity due to strong hydrophobic interactions.4. The effect of hydrophobic blocks contents on the aqueous properties of hydrophobically associating water-soluble polymersThe viscosities of synthesized hydrophobically associating water-soluble polymers enhanced with the increase of hydrophobic blocks content, yet the solubility of synthesized hydrophobically associating water-soluble polymers decreased with the increase of hydrophobic blocks content. The synthesized hydrophobically associating water-soluble polymers were insoluble if the hydrophobic blocks contents were higher than 1.5%.5. Salt-tolerence property of. synthesized hydrophobically associating water-solublepolymersThe viscosity of synthesized hydrophobically associating water-soluble polymers in different inorganic salts such as NaCl, KCl, BaCl2 and CaCl2 were detemined. The various inorganic salts have an positive effect on the viscosity of synthesized hydrophobically associating water-soluble polymers and the salts with high cation have a stronger influence than the salts with low cation.6. The effect of surfactants on the aqueous properties of hydrophobically associating water-soluble polymersThe viscosity of synthesized hydrophobically associating water-soluble polymers decreased with the increase of surfactant concentration, then enhanced as the surfactant concetration increased, and dropped as surfactant concentration reached higher degree.7. The temperature-tolerance property of. synthesized hydrophobically associating water-soluble polymersCompared to hydrophobically associating water-soluble polymers based on acrylamide,the temperature-tolerance property of synthesized hydrophobically associating water-soluble polymers is much better because of its more rigid molecular chain originated from N-vinyl pyrrolidone as hydrophobic monomer. The decomposition temperature of synthesized hydrophobically associating water-soluble polymers reached 400 °C.
|
PDF Full Text Request