Synthesis And Properties Of Cationic Hydrophobic Associate Polymers

Petroleum is one of the most important primary energy in the 21st century. With the rapid development of social economy, the demand for petroleum is growing.However, the resource of conventional petroleum is limited. After decades of exploration, it has dried up. So a lot of heavy oil resource become a hot topic. With the improvement of production technology, heavy oil resource is expected to be dominant in the energy to ease the world energy crisis.Heavy oil has high viscosity, high freezing point and poor liquidity characteristics, which bring great difficulties in mining and transportation of heavy oil.In order to overcome these difficulties, we should to reduce the viscosity of heavy oil.Commonly used technologies of viscosity reduction are: dilution, heating, emulsion and oil-soluble viscosity reducer. The emulsifying technology of viscosity reduction due to the obvious effect, low cost and simple technology has attracted much attention and widely used.The work of this paper mainly studies the synthesis and characterization of polymers, the aggregation behavior of copolymer solution and the viscosity reduction performance of heavy oil.1. The cationic monomer N- (3-dimethylhexadecylpropylammonium bromide)acrylamide (DMPHDBA) was synthesized by quatermarization of N-(3-dimethylaminopropyl) acrylamide with bromhexadecyl, and then the copolymers were prepared by the copolymerization of acrylamide (AM), N-acrylamide morpholine (ACMO) and DMPHDBA. The structure of the copolymer was characterized by NMR and IR spectra. The aggregation behavior of the copolymer in aqueous solution was studied by dynamic light scattering. The interaction between copolymer and crude oil was studied by interfacial tension and contact angle measurement. In addition, the stability and viscosity of the copolymer and heavy oil were investigated. The cationic ingredient DMPHDBA makes the copolymer have certain emulsifying properties, and ACMO enhances the interaction between polymer and heavy oil components, which is beneficial to improve the stability of oil and water emulsion and greatly reduces the viscosity of heavy oil.2. The cationic monomer 4-vinylbenzyl dodecyldimethylammonium chloride(VBDDMAC) was synthesized by quatermarization of N, N-dimethyldodecylamine and 4-vinylbenzene, and then the copolymers were prepared by the copolymerization of acrylamide (AM), N-acrylamide morpholine (ACMO) and VBDDMAC. Eight different copolymers with different monomer ratios were synthesized. The structure of the copolymer was characterized by NMR and IR spectra. The aggregation behavior of the copolymer in aqueous solution was investigated by resonance light scattering.In addition, the interaction between the copolymer and the crude oil was investigated by interfacial tension and contact angle measurement. Finally, the viscosity reduction of the heavy oil was investigated. The results show that the cationic ingredient VBDDMAC makes the copolymer have some emulsifying properties, and the monomer ACMO enhances the interaction between polymer and heavy oil component to greatly reducing the viscosity of heavy oil.3. The cationic monomer allyldodecyldimethylammonium chloride (ADDMAC)was synthesized by quatermarization of N,N-dimethyldodecylamine and allyl chloride, and then the copolymers were prepared by the copolymerization of acrylamide AM), docosyl polyoxyethylene ether methacrylate (BEM) and ADDMAC.Three kinds of copolymers with different proportions of monomers were synthesized.The structure of the copolymer was characterized by NMR and IR spectra. The aggregation behavior of the copolymer in water was investigated by dynamic light scattering, resonance light scattering, fluorescence spectroscopy and contact angle. In addition, the copolymer and the heavy oil were mixed into an oil-water emulsion, and the viscosity reduction test of the copolymer was examined by the viscosity test.Studies have shown that cationic monomer ADDMAC and monomer BEM can make the polymer has a certain emulsifying properties, and the long hydrophobic alkyl chain in these monomers makes the polymer has a hydrophobic association, which are strengthened the interaction between copolymers and heavy oil.4. The cationic monomer epoxypropyl dodecyldimethylammonium chloride(EPDDMAC) was synthesized and then subjected to ring-opening etherification with xanthan gum under alkaline conditions. By changing the feed ratio of EPDDMAC,modified xanthan gum (XEAC) with different degree of etherification was obtained.The structure of the XEAC was characterized by NMR, IR spectra and elemental analysis. The aggregation behavior of the XEAC in aqueous solution was studied by dynamic light scattering and surface tension. It was found that the modified xanthan gum had good. surface activity, and it could be used for the viscosity reduction of heavy oil.