In this study, the emulsion homopolymerization system containing vinyl acetate, potassium persulfate, a new cationic polymeric surfactant and water was studied by the applying semi-continuous emulsion polymerization p...In this study, the emulsion homopolymerization system containing vinyl acetate, potassium persulfate, a new cationic polymeric surfactant and water was studied by the applying semi-continuous emulsion polymerization process. The effects of new polymeric emulsifier on the physicochemical properties of obtained vinyl acetate latexes were investigated depending on vinyl acetate percentage in the polymerization recipe, and two thermal initiators in homopolymerization.展开更多
A polyacrylate emulsion containing sodium dodecyl sulfate(SDS) as a stabilizer was mixed with cetyltrimethyl ammonium chloride(CTAC) and a cationic surfactant containing an oxide ethylene chain(OEMD-20),respectively.T...A polyacrylate emulsion containing sodium dodecyl sulfate(SDS) as a stabilizer was mixed with cetyltrimethyl ammonium chloride(CTAC) and a cationic surfactant containing an oxide ethylene chain(OEMD-20),respectively.The results of experiment show that the mixtures of CTAC and PAE had higher conductivities than PAE;The mixtures of OEMD-20 had lower conductivities than PAE.展开更多
Styrene-acrylate latex with high glass transition temperature （T）, low minimum film forming temperature（MFT） and good stability was prepared via core-shell emulsion polymerization. With semicontinuous process, hig...Styrene-acrylate latex with high glass transition temperature （T）, low minimum film forming temperature（MFT） and good stability was prepared via core-shell emulsion polymerization. With semicontinuous process, high conversion rate of monomer and low gel rate were achieved. The weight ratio of core monomer to shell monomer was approximately 1.35. It is found that many factors such as emulsifiers, initiators, reaction temperature, pH value and polymerization technology have influences on the permormance of styrene-acrylate latex. The prepared latex was characterized by TEM and FTIR. The obtained latex with T of 20.57 ℃, MFT or5.0 ℃, and good stability, had good stability of film forming.展开更多
In well stimulation treatments using hydrochloric acid,undesirable water-in-oil emulsion and acid sludge may produce and then cause operational problems in oil field development.The processes intensify in the presence...In well stimulation treatments using hydrochloric acid,undesirable water-in-oil emulsion and acid sludge may produce and then cause operational problems in oil field development.The processes intensify in the presence of Fe(Ⅲ),which are from the corroded surfaces of field equipment and/or iron-bearing minerals of the oil reservoir.In order to understand the reasons of the stability of acid emulsions,acid emulsions were prepared by mixing crude oil emulsion with 15% hydrochloric acid solutions with and without Fe(Ⅲ) and then separated into free and upper(water free) and intermediate(with water) layers.It is assumed that the oil phase of the free and upper layers contains the compounds which do not participate in the formation of acid emulsions,and the oil phase of the intermediate layers contains components involved in the formation of oil/acid interface.The composition of the oil phase of each layer of the emulsions was studied.It is found that the asphaltenes with a high content of sulfur,oxygen and metals as well the flocculated material of protonated non-polar oil components are concentrated at the oil/acid interface.In addition to the above,in the presence of Fe(Ⅲ) the Fe(Ⅲ)-based complexes with polar groups of asphaltenes are formed at the acid/oil interface,contributing to the formation of armor films which enhance the emulsion stability.展开更多
The cationic graft copolymer was synthesized by reversed phase emulsion copolymerization of starch with diallydimethyl ammoniumlchlorid (DADMAC) and acrylamide(AM). The copolymerization was carried out using (NH4)2S2O...The cationic graft copolymer was synthesized by reversed phase emulsion copolymerization of starch with diallydimethyl ammoniumlchlorid (DADMAC) and acrylamide(AM). The copolymerization was carried out using (NH4)2S2O8-NH2CONH2 redox as initiator and selecting Span-20 as emulsifier. The effects of emulsifier content in oil phase, volume ratio of oil to water, initiator concentration and mole ratio of DADMAC to AM on the graft copolymerization were discussed. The optimum condition of synthetics was found with the orthogonal test method.展开更多
A poly(ethylene glycol) (PEG) based macroinitiator (MI) with terminal chloride atom at both ends was prepared by the reaction of PEG-400 with chloroacetyl chloride and used for the cationic polymerization of dodecyl v...A poly(ethylene glycol) (PEG) based macroinitiator (MI) with terminal chloride atom at both ends was prepared by the reaction of PEG-400 with chloroacetyl chloride and used for the cationic polymerization of dodecyl vinyl ether (DVE) yielding ABA type block copolymer. The block copolymer was then used as the surfactant for the emulsion polymerization of vinyl acetate and styrene in the presence of potassium persulfate as an initiator. The effects of new polymeric emulsifier on the physicochemical properties of obtained latexes were investigated depending on surfactant percentage in homopolymerizations.展开更多
文摘In this study, the emulsion homopolymerization system containing vinyl acetate, potassium persulfate, a new cationic polymeric surfactant and water was studied by the applying semi-continuous emulsion polymerization process. The effects of new polymeric emulsifier on the physicochemical properties of obtained vinyl acetate latexes were investigated depending on vinyl acetate percentage in the polymerization recipe, and two thermal initiators in homopolymerization.
文摘A polyacrylate emulsion containing sodium dodecyl sulfate(SDS) as a stabilizer was mixed with cetyltrimethyl ammonium chloride(CTAC) and a cationic surfactant containing an oxide ethylene chain(OEMD-20),respectively.The results of experiment show that the mixtures of CTAC and PAE had higher conductivities than PAE;The mixtures of OEMD-20 had lower conductivities than PAE.
文摘Styrene-acrylate latex with high glass transition temperature （T）, low minimum film forming temperature（MFT） and good stability was prepared via core-shell emulsion polymerization. With semicontinuous process, high conversion rate of monomer and low gel rate were achieved. The weight ratio of core monomer to shell monomer was approximately 1.35. It is found that many factors such as emulsifiers, initiators, reaction temperature, pH value and polymerization technology have influences on the permormance of styrene-acrylate latex. The prepared latex was characterized by TEM and FTIR. The obtained latex with T of 20.57 ℃, MFT or5.0 ℃, and good stability, had good stability of film forming.
文摘In well stimulation treatments using hydrochloric acid,undesirable water-in-oil emulsion and acid sludge may produce and then cause operational problems in oil field development.The processes intensify in the presence of Fe(Ⅲ),which are from the corroded surfaces of field equipment and/or iron-bearing minerals of the oil reservoir.In order to understand the reasons of the stability of acid emulsions,acid emulsions were prepared by mixing crude oil emulsion with 15% hydrochloric acid solutions with and without Fe(Ⅲ) and then separated into free and upper(water free) and intermediate(with water) layers.It is assumed that the oil phase of the free and upper layers contains the compounds which do not participate in the formation of acid emulsions,and the oil phase of the intermediate layers contains components involved in the formation of oil/acid interface.The composition of the oil phase of each layer of the emulsions was studied.It is found that the asphaltenes with a high content of sulfur,oxygen and metals as well the flocculated material of protonated non-polar oil components are concentrated at the oil/acid interface.In addition to the above,in the presence of Fe(Ⅲ) the Fe(Ⅲ)-based complexes with polar groups of asphaltenes are formed at the acid/oil interface,contributing to the formation of armor films which enhance the emulsion stability.
文摘The cationic graft copolymer was synthesized by reversed phase emulsion copolymerization of starch with diallydimethyl ammoniumlchlorid (DADMAC) and acrylamide(AM). The copolymerization was carried out using (NH4)2S2O8-NH2CONH2 redox as initiator and selecting Span-20 as emulsifier. The effects of emulsifier content in oil phase, volume ratio of oil to water, initiator concentration and mole ratio of DADMAC to AM on the graft copolymerization were discussed. The optimum condition of synthetics was found with the orthogonal test method.
基金This work were supported by the Turkish Scientific and Technological Research Council(TUBITAK)(Project Number:108T722)Scientific Research Projects Coordination Center of Yildiz Technical University(Project Number:2012-01-02-KAP04).
文摘A poly(ethylene glycol) (PEG) based macroinitiator (MI) with terminal chloride atom at both ends was prepared by the reaction of PEG-400 with chloroacetyl chloride and used for the cationic polymerization of dodecyl vinyl ether (DVE) yielding ABA type block copolymer. The block copolymer was then used as the surfactant for the emulsion polymerization of vinyl acetate and styrene in the presence of potassium persulfate as an initiator. The effects of new polymeric emulsifier on the physicochemical properties of obtained latexes were investigated depending on surfactant percentage in homopolymerizations.
