In this paper, cationic polyacrylamide microspheres （CPAM） were synthesized using acrylamide （AM） and methacryloyloxyethyl trimethyl ammonium chloride （TMAEMC） as monomers, ammonium sulfate as dispersant, poly（...In this paper, cationic polyacrylamide microspheres （CPAM） were synthesized using acrylamide （AM） and methacryloyloxyethyl trimethyl ammonium chloride （TMAEMC） as monomers, ammonium sulfate as dispersant, poly（acryloyloxyethyl trimethyl ammonium chloride） （PAETAC） as dispersion stabilizer, and ammonium persulfate as initiator. The synthetic method was dispersion polymerization. The effects of monomer ratio （AM/TMAEMC）, dispersant concentration, and dispersion stabilizer dosage on dispersion polymerization were systematically studied to determine the optimal preparation conditions. The structure and viscosity of the synthesized polymer were characterized by FTIR and capillary viscometry, respectively, and the particle sizes and distribution of the polymer microspheres were characterized by microscopy and dynamic light scattering, respectively. Finally, flow tests were conducted to measure the permeability reduction performance of the microspheres at various concentrations in sand packs with different permeability. Results show that CPAM emulsion of a solids content of 1 wt% has excellent performance in low-to-medium permeability formations （〈 1,000 mD）, and the efficiency may reach above 90%.展开更多
Tertiary amine cationic polyacrylamide with high cationization degree was used as a new cationic agent to pretreat cotton with dip-pad-bake method. The obtained cationic cotton was dyed with reactive dyes in the ab-se...Tertiary amine cationic polyacrylamide with high cationization degree was used as a new cationic agent to pretreat cotton with dip-pad-bake method. The obtained cationic cotton was dyed with reactive dyes in the ab-sence of electrolyte. The effects of the characteristics of the cationic agent and the pretreatment conditions on dye-ability of reactive dye were investigated. The results showed that the fixation and K/S values of the reactive dyes on the cationic cotton were improved compared with those on the untreated one in the presence of salt. Tests on fast-ness properties of the dyed cotton and fabric quality of the pretreated cotton were carried out and the results showed that wash and rub fastness of the salt-free dyeing were both satisfactory. And anti-crease property,tensile and tear strength,and handling of the cationic cotton were also good compared with that of the untreated one.展开更多
Based on the analyses of crystal structures and surface properties of diaspore and kaolinite, an effective diaspore depressant, CPAM(cationic polyacrylamide) polymers was discovered by single minerals tests, separatio...Based on the analyses of crystal structures and surface properties of diaspore and kaolinite, an effective diaspore depressant, CPAM(cationic polyacrylamide) polymers was discovered by single minerals tests, separation experiments of artificial mixed minerals, zetapotential and adsorption measurement. The reverse flotation separation on diaspore and kaolinite can be carried out using collector dodecylamine acetate and depressant CPAM under pH 5.5 8.5. On the surfaces of diaspore, there are a large amount of active aluminum atoms. They can bond with -C(O)NH 2 groups in CPAM and make the -CH 2N +(CH 3) 3 groups in CPAM orient toward the outer surfaces of diaspore, which prevents a majority of the dodecylamine cations from adsorbing on diaspore, enhances hydrophilicity of diaspore, and depresses the floatability of diaspore. But for kaolinite, CPAM polymers have little effect on its floatability.展开更多
The characteristics of soil treated with cationic polyacrylamide(CPAM)mass content of 0%,0.2%,0.4%,0.6%,0.8%,and 1%were investigated through a series of laboratory tests to explore the practical engineering effect of ...The characteristics of soil treated with cationic polyacrylamide(CPAM)mass content of 0%,0.2%,0.4%,0.6%,0.8%,and 1%were investigated through a series of laboratory tests to explore the practical engineering effect of an expansive soil amended with environmental protection material CPAM.The results indicate that with the increasing CPAM content,the liquid limit and plasticity index of soil decrease,the plastic limit increases,and the free swelling ratio and loaded swelling ratio decrease.Besides,the improved soil has less disintegrating property and better water stability.The shear strength increases as the content increases,and the optimal content is 0.6%.Meanwhile,the cohesion of the soil first increases and then decreases,and the internal friction angle increases.Additionally,the unconfined compressive strength first increases and then decreases.The improved soil presents the characteristics of brittle failure and reaches the peak value(410.1 kPa)at the content of 0.8%after curing for 14 days.Scanning electron microscope(SEM)exhibits that the number of curved and wrinkled sections of the expansive soil is reduced after CPAM improvement.Simultaneously,the arrangement of the superimposed polymer changes from face-face to side-angle or side-face-angle,and the reticular structure formed improves the strength and spatial stability of the soil.Therefore,adding appropriate cationic polyacrylamide could improve expansive soil in engineering.展开更多
Cationic polyacrylamide(CPAM) which was prepared through complex initiation system in laboratory and cationic polyacrylamide(Ciba) were used as retention and drainage aids for bleached wheat straw pulp. The influences...Cationic polyacrylamide(CPAM) which was prepared through complex initiation system in laboratory and cationic polyacrylamide(Ciba) were used as retention and drainage aids for bleached wheat straw pulp. The influences of (polydiallyldimethlammonium chloride) PDADMAC and PDADMAC/CPAM on Zeta potential and drainability of pulp was investigated. The dual drainage and retention systems such as CPAM/modified bentonite, CPAM/colloidal SiO2, as well as their comparison between the two systems were discussed, and the optimal dosages of additives were determined. The results showed that: the complex systems can further enhance filler retention, drainability of pulp and strength properties of paper.展开更多
基金financial support from the National Natural Science Foundation of China (Grants Nos. 51203186, U1362101 and 51173203)the Converging Research Center Program funded by Korean Ministry of Education (2013K000415)the Project of Science and Technology Program for Basic Research of Qingdao (No. 121-4-7-(6)-jch)
文摘In this paper, cationic polyacrylamide microspheres （CPAM） were synthesized using acrylamide （AM） and methacryloyloxyethyl trimethyl ammonium chloride （TMAEMC） as monomers, ammonium sulfate as dispersant, poly（acryloyloxyethyl trimethyl ammonium chloride） （PAETAC） as dispersion stabilizer, and ammonium persulfate as initiator. The synthetic method was dispersion polymerization. The effects of monomer ratio （AM/TMAEMC）, dispersant concentration, and dispersion stabilizer dosage on dispersion polymerization were systematically studied to determine the optimal preparation conditions. The structure and viscosity of the synthesized polymer were characterized by FTIR and capillary viscometry, respectively, and the particle sizes and distribution of the polymer microspheres were characterized by microscopy and dynamic light scattering, respectively. Finally, flow tests were conducted to measure the permeability reduction performance of the microspheres at various concentrations in sand packs with different permeability. Results show that CPAM emulsion of a solids content of 1 wt% has excellent performance in low-to-medium permeability formations （〈 1,000 mD）, and the efficiency may reach above 90%.
基金Supported by the National Science Foundation for Distinguished Young Scholar of China（20525620） the National Natural Science Foundation of China（20806013） the Program for Changjiang Scholar and Innovative Research Team in University（IRT 0711）
文摘Tertiary amine cationic polyacrylamide with high cationization degree was used as a new cationic agent to pretreat cotton with dip-pad-bake method. The obtained cationic cotton was dyed with reactive dyes in the ab-sence of electrolyte. The effects of the characteristics of the cationic agent and the pretreatment conditions on dye-ability of reactive dye were investigated. The results showed that the fixation and K/S values of the reactive dyes on the cationic cotton were improved compared with those on the untreated one in the presence of salt. Tests on fast-ness properties of the dyed cotton and fabric quality of the pretreated cotton were carried out and the results showed that wash and rub fastness of the salt-free dyeing were both satisfactory. And anti-crease property,tensile and tear strength,and handling of the cationic cotton were also good compared with that of the untreated one.
文摘Based on the analyses of crystal structures and surface properties of diaspore and kaolinite, an effective diaspore depressant, CPAM(cationic polyacrylamide) polymers was discovered by single minerals tests, separation experiments of artificial mixed minerals, zetapotential and adsorption measurement. The reverse flotation separation on diaspore and kaolinite can be carried out using collector dodecylamine acetate and depressant CPAM under pH 5.5 8.5. On the surfaces of diaspore, there are a large amount of active aluminum atoms. They can bond with -C(O)NH 2 groups in CPAM and make the -CH 2N +(CH 3) 3 groups in CPAM orient toward the outer surfaces of diaspore, which prevents a majority of the dodecylamine cations from adsorbing on diaspore, enhances hydrophilicity of diaspore, and depresses the floatability of diaspore. But for kaolinite, CPAM polymers have little effect on its floatability.
基金funded by the National Natural Science Foundation of China(41977236,41672278,41271071)the Science and Technology Planning Project of Housing and Urban-Rural Development of Anhui Province(2019-YF023)+1 种基金the Major Universities Natural Science Research Project in Anhui Province(KJ2016SD19)the Natural Science Foundation of Jiangxi Province(2019ACBL20002).
文摘The characteristics of soil treated with cationic polyacrylamide(CPAM)mass content of 0%,0.2%,0.4%,0.6%,0.8%,and 1%were investigated through a series of laboratory tests to explore the practical engineering effect of an expansive soil amended with environmental protection material CPAM.The results indicate that with the increasing CPAM content,the liquid limit and plasticity index of soil decrease,the plastic limit increases,and the free swelling ratio and loaded swelling ratio decrease.Besides,the improved soil has less disintegrating property and better water stability.The shear strength increases as the content increases,and the optimal content is 0.6%.Meanwhile,the cohesion of the soil first increases and then decreases,and the internal friction angle increases.Additionally,the unconfined compressive strength first increases and then decreases.The improved soil presents the characteristics of brittle failure and reaches the peak value(410.1 kPa)at the content of 0.8%after curing for 14 days.Scanning electron microscope(SEM)exhibits that the number of curved and wrinkled sections of the expansive soil is reduced after CPAM improvement.Simultaneously,the arrangement of the superimposed polymer changes from face-face to side-angle or side-face-angle,and the reticular structure formed improves the strength and spatial stability of the soil.Therefore,adding appropriate cationic polyacrylamide could improve expansive soil in engineering.
文摘Cationic polyacrylamide(CPAM) which was prepared through complex initiation system in laboratory and cationic polyacrylamide(Ciba) were used as retention and drainage aids for bleached wheat straw pulp. The influences of (polydiallyldimethlammonium chloride) PDADMAC and PDADMAC/CPAM on Zeta potential and drainability of pulp was investigated. The dual drainage and retention systems such as CPAM/modified bentonite, CPAM/colloidal SiO2, as well as their comparison between the two systems were discussed, and the optimal dosages of additives were determined. The results showed that: the complex systems can further enhance filler retention, drainability of pulp and strength properties of paper.
