Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carbo...Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.展开更多
The emeraldine base form of polyaniline (PANI) can be doped by a photo-induced doping method. In this method a. copolymer of vinylidene chloride and methyl acrylate (VCMAC) was used as photo acid generator which can r...The emeraldine base form of polyaniline (PANI) can be doped by a photo-induced doping method. In this method a. copolymer of vinylidene chloride and methyl acrylate (VCMAC) was used as photo acid generator which can release proton when it is exposed to ultraviolet light (lambda = 254 nm). The structure of PANI-VCMAC system before and after irradiation was characterized by elemental analysis, IR, XTP, anti SEM images. Results obtained indicate that the photo-induced doping characteristics, such as doping position and type of charge carriers, are similar to that of PANI doped with HCl. The poor room-temperature conductivity (similar to 10-S-5/cm) of PANI-VCMAC system after irradiation may be due to low doping degree (similar to pH=3) and the difference in morphology as compared with PANI-HCl film.展开更多
Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl...Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction termi-nating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emul-sion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containingvarious concentrations of PEO-A was studied. In all cases stable emulsion coplymerizationsof MMA and BA were obtained. The stabilizing effect was found to be dependent on themolecular weight and the feed amount of the macromonomer.展开更多
The catalytic activities of some heteropolyacids(HPAs) in synthesizing butyl acrylate are reported. It has been demonstrated that 12 tungstophosphoric acid is the most effective catalyst among more than 20 HPA(s...The catalytic activities of some heteropolyacids(HPAs) in synthesizing butyl acrylate are reported. It has been demonstrated that 12 tungstophosphoric acid is the most effective catalyst among more than 20 HPA(salts). Various factors concerned in this reaction have been investigated. The optimum conditions have been found, that is, the molar ratio of alcohol to acid is 1.2∶1.0 , the catalyst concentration 1%(mass fraction), the reaction time 2 h, the temperature 98—124 ℃ and a certain amount of polymerization inhibitor exists.展开更多
In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safe...In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...展开更多
This study aims to beneficiate low grade goethitic iron ore fines using a selective flocculation process. Selective flocculation studies were conducted using different polymers such as starch amylopectin(AP), poly acr...This study aims to beneficiate low grade goethitic iron ore fines using a selective flocculation process. Selective flocculation studies were conducted using different polymers such as starch amylopectin(AP), poly acrylic acid(PAA), and a graft copolymer(AP-g-PAA). The obtained results were analyzed; they indicate the enhancement of the iron ore grade from 58.49% to 67.52% using AP-g-PAA with a recovery of 95.08%. In addition, 64.45% Fe with a recovery of 88.79% was obtained using AP. Similarly, using PAA, the grade increased to 63.46% Fe with a recovery of 82.10%. The findings are also supported by characterizing concentrates using X-ray diffraction(XRD) and electron probe microanalysis(EPMA) techniques.展开更多
In this report,zinc acrylate copolymers were synthesized by used different organic acid as the side chain structure.These copolymers were further characterized by GPC,DSC and Water absorption analysis respectively,and...In this report,zinc acrylate copolymers were synthesized by used different organic acid as the side chain structure.These copolymers were further characterized by GPC,DSC and Water absorption analysis respectively,and then the effects of the chain structure of organic acid on hydrolysis degradation and copper release rate were also discussed.In the meantime,the result shows that the biocide release rate could be controlled by used different chain structure of organic acid.展开更多
半导电屏蔽材料是制造高压电缆的关键组分,但仍存在电阻率高及其稳定性差难题。基于此,该文提出构筑双逾渗网络结构思路,选择乙烯-丙烯酸丁酯共聚物(ethylene-butyl acrylate copolymer,EBA)和低密度聚乙烯(low density polyethylene,LD...半导电屏蔽材料是制造高压电缆的关键组分,但仍存在电阻率高及其稳定性差难题。基于此,该文提出构筑双逾渗网络结构思路,选择乙烯-丙烯酸丁酯共聚物(ethylene-butyl acrylate copolymer,EBA)和低密度聚乙烯(low density polyethylene,LDPE)作为基体、导电炭黑(conductive carbon black,CB)作为导电填料制备半导电屏蔽材料,系统研究半导电屏蔽材料结构演变规律,评价半导电屏蔽材料结晶行为、电学性能、力学性能、表面光洁度等关键性能。实验结果表明:EBA与LDPE质量比为6:4时,半导电屏蔽材料内部形成双逾渗导电网络结构,相比于常规分布结构,其23和90℃的体积电阻率分别降低46.7%和74.4%,对应的正温度系数(positive temperature coefficient,PTC)降低52.1%,表明具有良好的电阻率稳定性。此外,该半导电屏蔽材料还具有优异的力学性能和表面光洁度。该结果可为高压电缆半导电屏蔽材料开发提供一定理论基础与数据支撑。展开更多
An attempt was made in the paper aiming at imparting flame retardancy to polymers by plasma grafting technique Based on EVA copolymers with different VA contents the author tried to use the Ar plasma followed by graf...An attempt was made in the paper aiming at imparting flame retardancy to polymers by plasma grafting technique Based on EVA copolymers with different VA contents the author tried to use the Ar plasma followed by grafting with/without subsequent saponification and metal ion exchange expediting the charring of polymers upon heationg Characterization of the flammability of the plasma treated EVA copolymers grafted with acrylic monomers(MAA,AA and AAm)indicates that this approach turns out to be a promising way and worthy doing whatever in research and/or applications展开更多
Under the specially designated condition the polymerization of both tetrahydrofuran (THF) and tert-butyl methacrylate (tBMA) is a living one. The diblock copolymer, poly(tert-butyl methacrylate)-block-polytetrahydrofu...Under the specially designated condition the polymerization of both tetrahydrofuran (THF) and tert-butyl methacrylate (tBMA) is a living one. The diblock copolymer, poly(tert-butyl methacrylate)-block-polytetrahydrofuran (PtBMA-b-PTHF), was successfully synthesized by meansof the coupling reaction of living cationic PTHF+, SbF6 with living anionic PtBMA-, Li+. LiCI, whichhas a beneficial effect on the molecular weight distribution (MWD) in the anionic polymerization of (meth)acrylates, hinders the coupling reaction of living chains and cannot be used in the preparation of tBMA precursor. The hydrolysis of the aforementioned diblock copolymer under acid condition results in the amphiphilic diblock copolymer, i.e. poly(methyl acrylic acid)-block-polytetra-hydrofuran (PMAA-b-PTHF). The diblock copolymers were characterized with GPC and IR.展开更多
Effects of branches on the crystallization kinetics of polypropylene-g-polystyrene （PP-g-PS） and polypropylene-g- poly（n-butyl acrylate） （PP-g-PnBA） graft copolymers with well-defined molecular structures were s...Effects of branches on the crystallization kinetics of polypropylene-g-polystyrene （PP-g-PS） and polypropylene-g- poly（n-butyl acrylate） （PP-g-PnBA） graft copolymers with well-defined molecular structures were systematically investigated by DSC. The Avrami equation was used to analyze the isothermal crystallization process, while the analysis of nonisothermal crystallization process was based on the Jeziorny-modified Avrami model and Mo model. The kinetics results of isothermal and nonisothermal crystallization verified the peculiar effects of branches on the crystallization process of PP backbones in PP-g-PS and PP-g-PnBA graft copolymers： on one hand, the interaction between branches （n-n interaction between PS branches, or dipole-dipole interaction between PnBA branches） restrained the mobility and reptation ability of the PP backbones, which hindered the crystallization process; on the other hand, the heterogeneous nucleation effect resulting from the branched structure and fluctuation-assisted nucleation mechanism （caused by microphase separation between the PS or PnBA rich phase and the PP rich phase） became more pronounced with increasing branch length, which facilitated the crystallization process.展开更多
Nanostructure fabrication from block copolymers in my group normally involves polymer design, synthesis, self-assembly, selective domain crosslinking, and sometimes selective domain removal. Preparation of thin films ...Nanostructure fabrication from block copolymers in my group normally involves polymer design, synthesis, self-assembly, selective domain crosslinking, and sometimes selective domain removal. Preparation of thin films withnanochannels was used to illustrate the strategy we took. In this particular case, a linear triblock copolymer polyisoprenc-block-poly(2-cinnamoylethyl methacrylate)-block-poly(t-butyl acrylate), PI-b-PCEMA-b-PtBA, was used. Films, 25 to50 μm thick, were prepared from casting on glass slides a toluene solution of PI-b-PCEMA-b-PtBA and PtBA homopolymer,hPtBA, where hPtBA is shorter than the PtBA block. At the hPtBA mass faction of 20% relative to the triblock or the totalPtBA (hPtBA and PtBA block) volume fraction of 0.44, hPtBA and PtBA formed a seemingly continuous phase in the matrixof PCEMA and Pl. Such a block segregation pattern was locked in by photocrosslinking the PCEMA domain. Nanochannelswere formed by extracting out hPtBA with solvent. Alternatively. larger channels were obtained from extracting out hPtBAand hydrolyzing the t-butyl groups of the PtBA block. Such membranes were not liquid permeable but had gas permeabilityconstants ～6 orders of magnitude higher than that of low-density polyethylene films.展开更多
基金Project (21176264) supported by the National Natural Science Foundation of ChinaProject (11JJ2010) supported by Hunan Provincial Natural Science Foundation of ChinaProject (LC13076) supported by Undergraduate Innovation Foundation of Central South University,China
文摘Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.
基金The work was supported by the National Natural Science Foundation of China
文摘The emeraldine base form of polyaniline (PANI) can be doped by a photo-induced doping method. In this method a. copolymer of vinylidene chloride and methyl acrylate (VCMAC) was used as photo acid generator which can release proton when it is exposed to ultraviolet light (lambda = 254 nm). The structure of PANI-VCMAC system before and after irradiation was characterized by elemental analysis, IR, XTP, anti SEM images. Results obtained indicate that the photo-induced doping characteristics, such as doping position and type of charge carriers, are similar to that of PANI doped with HCl. The poor room-temperature conductivity (similar to 10-S-5/cm) of PANI-VCMAC system after irradiation may be due to low doping degree (similar to pH=3) and the difference in morphology as compared with PANI-HCl film.
文摘Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction termi-nating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emul-sion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containingvarious concentrations of PEO-A was studied. In all cases stable emulsion coplymerizationsof MMA and BA were obtained. The stabilizing effect was found to be dependent on themolecular weight and the feed amount of the macromonomer.
文摘The catalytic activities of some heteropolyacids(HPAs) in synthesizing butyl acrylate are reported. It has been demonstrated that 12 tungstophosphoric acid is the most effective catalyst among more than 20 HPA(salts). Various factors concerned in this reaction have been investigated. The optimum conditions have been found, that is, the molar ratio of alcohol to acid is 1.2∶1.0 , the catalyst concentration 1%(mass fraction), the reaction time 2 h, the temperature 98—124 ℃ and a certain amount of polymerization inhibitor exists.
文摘In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...
基金the National Metallurgical Laboratory,Jamshedpur for their kind support
文摘This study aims to beneficiate low grade goethitic iron ore fines using a selective flocculation process. Selective flocculation studies were conducted using different polymers such as starch amylopectin(AP), poly acrylic acid(PAA), and a graft copolymer(AP-g-PAA). The obtained results were analyzed; they indicate the enhancement of the iron ore grade from 58.49% to 67.52% using AP-g-PAA with a recovery of 95.08%. In addition, 64.45% Fe with a recovery of 88.79% was obtained using AP. Similarly, using PAA, the grade increased to 63.46% Fe with a recovery of 82.10%. The findings are also supported by characterizing concentrates using X-ray diffraction(XRD) and electron probe microanalysis(EPMA) techniques.
文摘In this report,zinc acrylate copolymers were synthesized by used different organic acid as the side chain structure.These copolymers were further characterized by GPC,DSC and Water absorption analysis respectively,and then the effects of the chain structure of organic acid on hydrolysis degradation and copper release rate were also discussed.In the meantime,the result shows that the biocide release rate could be controlled by used different chain structure of organic acid.
文摘半导电屏蔽材料是制造高压电缆的关键组分,但仍存在电阻率高及其稳定性差难题。基于此,该文提出构筑双逾渗网络结构思路,选择乙烯-丙烯酸丁酯共聚物(ethylene-butyl acrylate copolymer,EBA)和低密度聚乙烯(low density polyethylene,LDPE)作为基体、导电炭黑(conductive carbon black,CB)作为导电填料制备半导电屏蔽材料,系统研究半导电屏蔽材料结构演变规律,评价半导电屏蔽材料结晶行为、电学性能、力学性能、表面光洁度等关键性能。实验结果表明:EBA与LDPE质量比为6:4时,半导电屏蔽材料内部形成双逾渗导电网络结构,相比于常规分布结构,其23和90℃的体积电阻率分别降低46.7%和74.4%,对应的正温度系数(positive temperature coefficient,PTC)降低52.1%,表明具有良好的电阻率稳定性。此外,该半导电屏蔽材料还具有优异的力学性能和表面光洁度。该结果可为高压电缆半导电屏蔽材料开发提供一定理论基础与数据支撑。
文摘An attempt was made in the paper aiming at imparting flame retardancy to polymers by plasma grafting technique Based on EVA copolymers with different VA contents the author tried to use the Ar plasma followed by grafting with/without subsequent saponification and metal ion exchange expediting the charring of polymers upon heationg Characterization of the flammability of the plasma treated EVA copolymers grafted with acrylic monomers(MAA,AA and AAm)indicates that this approach turns out to be a promising way and worthy doing whatever in research and/or applications
文摘Under the specially designated condition the polymerization of both tetrahydrofuran (THF) and tert-butyl methacrylate (tBMA) is a living one. The diblock copolymer, poly(tert-butyl methacrylate)-block-polytetrahydrofuran (PtBMA-b-PTHF), was successfully synthesized by meansof the coupling reaction of living cationic PTHF+, SbF6 with living anionic PtBMA-, Li+. LiCI, whichhas a beneficial effect on the molecular weight distribution (MWD) in the anionic polymerization of (meth)acrylates, hinders the coupling reaction of living chains and cannot be used in the preparation of tBMA precursor. The hydrolysis of the aforementioned diblock copolymer under acid condition results in the amphiphilic diblock copolymer, i.e. poly(methyl acrylic acid)-block-polytetra-hydrofuran (PMAA-b-PTHF). The diblock copolymers were characterized with GPC and IR.
基金financially supported by the National Natural Science Foundation of China for the projects(Nos.51233005 and 51073149)
文摘Effects of branches on the crystallization kinetics of polypropylene-g-polystyrene （PP-g-PS） and polypropylene-g- poly（n-butyl acrylate） （PP-g-PnBA） graft copolymers with well-defined molecular structures were systematically investigated by DSC. The Avrami equation was used to analyze the isothermal crystallization process, while the analysis of nonisothermal crystallization process was based on the Jeziorny-modified Avrami model and Mo model. The kinetics results of isothermal and nonisothermal crystallization verified the peculiar effects of branches on the crystallization process of PP backbones in PP-g-PS and PP-g-PnBA graft copolymers： on one hand, the interaction between branches （n-n interaction between PS branches, or dipole-dipole interaction between PnBA branches） restrained the mobility and reptation ability of the PP backbones, which hindered the crystallization process; on the other hand, the heterogeneous nucleation effect resulting from the branched structure and fluctuation-assisted nucleation mechanism （caused by microphase separation between the PS or PnBA rich phase and the PP rich phase） became more pronounced with increasing branch length, which facilitated the crystallization process.
文摘Nanostructure fabrication from block copolymers in my group normally involves polymer design, synthesis, self-assembly, selective domain crosslinking, and sometimes selective domain removal. Preparation of thin films withnanochannels was used to illustrate the strategy we took. In this particular case, a linear triblock copolymer polyisoprenc-block-poly(2-cinnamoylethyl methacrylate)-block-poly(t-butyl acrylate), PI-b-PCEMA-b-PtBA, was used. Films, 25 to50 μm thick, were prepared from casting on glass slides a toluene solution of PI-b-PCEMA-b-PtBA and PtBA homopolymer,hPtBA, where hPtBA is shorter than the PtBA block. At the hPtBA mass faction of 20% relative to the triblock or the totalPtBA (hPtBA and PtBA block) volume fraction of 0.44, hPtBA and PtBA formed a seemingly continuous phase in the matrixof PCEMA and Pl. Such a block segregation pattern was locked in by photocrosslinking the PCEMA domain. Nanochannelswere formed by extracting out hPtBA with solvent. Alternatively. larger channels were obtained from extracting out hPtBAand hydrolyzing the t-butyl groups of the PtBA block. Such membranes were not liquid permeable but had gas permeabilityconstants ～6 orders of magnitude higher than that of low-density polyethylene films.
