Rare-earth ternary catalysts Y（CCl3COO）3-ZnR2-glycerin were prepared for the copolymerization of carbon dioxide and propylene oxide （PO）, where dialkylzincs （ZnR2） were diethylzinc, di（n-propyl）zinc, di（n-bu...Rare-earth ternary catalysts Y（CCl3COO）3-ZnR2-glycerin were prepared for the copolymerization of carbon dioxide and propylene oxide （PO）, where dialkylzincs （ZnR2） were diethylzinc, di（n-propyl）zinc, di（n-butyl）zinc, di（i-propyl）zinc, di（i-butyl）zinc, di（s-butyl）zinc,respectively. The Y（CCl3COO）3-ZnR2-glycerin catalysts displayed the highest catalytic activity at the molar ratio of Y（CCl3COO）3：ZnR2：glycerin = 1：20：10. In the same copolymerization condition, catalysts containing dialkylzincs with branched alkyl group showed lower catalytic activity than that with primary alkyl group. For those catalysts including dialkylzincs with primary alkyl group, their catalytic activity decreases with increasing number of carbon atom in the alkyl group with the following sequence： Y（CCl3COO）3-ZnEt2-glycerin 〉 Y（CCl3COO）3-Zn（n- Pr）2-glycerin〉Y（CCl3COO）3-Zn（n-Bu）2-glycerin. However, the alkyl group in the dialkylzinc does not influence the insertion of PO into the propagation chain end.展开更多
A novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) was prepared by cyclic voltammetry (CV) and characterized by FTIR and SEM. It showed good electroactivity for methanol oxidation in H2SO4 solution.
Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H...Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H-1-NMR analysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecular weight copolymers with various EO content were obtained and their values of molecular weight distribution (MWD) fell in the range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO+PO to initiator moles used, The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.展开更多
The preparation and electrocatalytic activity of polyaniline-poly （ propylene oxide ） （ PAN-PPO ） modified by Pt particles （ Pt/ PAN-PPO ） were investigated. Pt/ PAN-PPO was characterized by scanning electron mi...The preparation and electrocatalytic activity of polyaniline-poly （ propylene oxide ） （ PAN-PPO ） modified by Pt particles （ Pt/ PAN-PPO ） were investigated. Pt/ PAN-PPO was characterized by scanning electron microscopy （SEM） and energy dispersive spectroscopy （ EDS ）. Pt particles on PAN-PPO were in the nanometer range, and dispersed in a three-dimensional distribution on the surface of PAN-PPO film. Compared with polyaniline and glassy carbon modified with Pt particles under the same conditions, Pt/PAN-PPO exhibited a high electrocatalytic activity for lysine oxidation.展开更多
A series of ethylene oxide (EO)-propylene oxide (PO) randomco-polymers (EOPO) were used to form aqueous two-phase systems (ATPS)with ammonium sulfate. Effects of EOPO's properties on the phaseseparation behaviors ...A series of ethylene oxide (EO)-propylene oxide (PO) randomco-polymers (EOPO) were used to form aqueous two-phase systems (ATPS)with ammonium sulfate. Effects of EOPO's properties on the phaseseparation behaviors and on the partition of cephalexin and7-aminodesacetoxicephalosporanic acid (7-ADCA) in ATPS wereinvestigated. Both the molar mass and molar ratio of EO to PO of EOPOcould greatly influence partition behaviors of cephalexin and 7-ADCAas well as the binodal curve of ATPS.展开更多
The ring-opening copolymerization of adipic anhydride with propylene oxide was carried out with yttrium triflates as a catalyst. Poly（propylene adipate） could be synthesized by controlling the copolymerization condi...The ring-opening copolymerization of adipic anhydride with propylene oxide was carried out with yttrium triflates as a catalyst. Poly（propylene adipate） could be synthesized by controlling the copolymerization conditions. The copolymerization procedure was tracked by ^1H NMR analyses.展开更多
The copolymerization kinetics of ethylene oxide and propylene oxide in an atomizing-circulation reactorunder semi-continuous operation is studied which is of great importance for molecular designation. The kineticpara...The copolymerization kinetics of ethylene oxide and propylene oxide in an atomizing-circulation reactorunder semi-continuous operation is studied which is of great importance for molecular designation. The kineticparameters are obtained by numerical optimization of the kinetic model.展开更多
In this work, the surface activity of block copolymer nonionic surfactants (RPE) has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (Γ), surface area demand per molecule (A)...In this work, the surface activity of block copolymer nonionic surfactants (RPE) has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (Γ), surface area demand per molecule (A), surface tension at CMC (γCMC). A linear decrease of ln[CMC] vs number of oxypropylene units in copolymer molecule was observed. The change in the work of cohesion per oxypropylene group when passing from molecular into micellar state, calculated from the Shinoda equation, was 0.43kT for the studied compounds.展开更多
In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom ...In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom transfer radical polymerization(ATRP).The target products were confirmed by GPC and1H NMR.This well-defined copolymer can supply a promising material as drug and gene carriers and protective materials.展开更多
The electrocatalytic synthesis of propylene carbonate（PC） from CO2 and propylene oxide（PO） was studied under mild conditions（PCO2=1.01×105 Pa, t=25 ℃）. Influences of solvents, supporting electrolytes, the ...The electrocatalytic synthesis of propylene carbonate（PC） from CO2 and propylene oxide（PO） was studied under mild conditions（PCO2=1.01×105 Pa, t=25 ℃）. Influences of solvents, supporting electrolytes, the passed charge, the nature of electrodes and the current density（j） on the yield of PC were investigated to optimize the electrolytic conditions, with the maximal yield to be 46.2%, the selectivity of propylene carbonate is 100%. The reduction of propylene oxide in the absence and presence of CO2 was examined by cyclic voltammetry. The mechanism of the reaction initiated by the synergistic effect of halides ions of supporting electrolytes with nucleophilicity and the metal ions from scarification anode with Lewis acid acidity was proposed on the basis of our results.展开更多
Incorporation of strontium into V-Mo alumina-supported catalyst enhanced its performance (increased conversion and selectivity,decreased reducibility and improved stability) in propane oxydehydrogenation to propylene....Incorporation of strontium into V-Mo alumina-supported catalyst enhanced its performance (increased conversion and selectivity,decreased reducibility and improved stability) in propane oxydehydrogenation to propylene.12.5% Sr loading was shown to be the optimum content to the V-Mo catalyst.The results were supported by various characterization techniques,namely,BET,XRD,SEM,FTIR and TPD.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Nos.20025414 and 50003009).
文摘Rare-earth ternary catalysts Y（CCl3COO）3-ZnR2-glycerin were prepared for the copolymerization of carbon dioxide and propylene oxide （PO）, where dialkylzincs （ZnR2） were diethylzinc, di（n-propyl）zinc, di（n-butyl）zinc, di（i-propyl）zinc, di（i-butyl）zinc, di（s-butyl）zinc,respectively. The Y（CCl3COO）3-ZnR2-glycerin catalysts displayed the highest catalytic activity at the molar ratio of Y（CCl3COO）3：ZnR2：glycerin = 1：20：10. In the same copolymerization condition, catalysts containing dialkylzincs with branched alkyl group showed lower catalytic activity than that with primary alkyl group. For those catalysts including dialkylzincs with primary alkyl group, their catalytic activity decreases with increasing number of carbon atom in the alkyl group with the following sequence： Y（CCl3COO）3-ZnEt2-glycerin 〉 Y（CCl3COO）3-Zn（n- Pr）2-glycerin〉Y（CCl3COO）3-Zn（n-Bu）2-glycerin. However, the alkyl group in the dialkylzinc does not influence the insertion of PO into the propagation chain end.
文摘A novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) was prepared by cyclic voltammetry (CV) and characterized by FTIR and SEM. It showed good electroactivity for methanol oxidation in H2SO4 solution.
文摘Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H-1-NMR analysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecular weight copolymers with various EO content were obtained and their values of molecular weight distribution (MWD) fell in the range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO+PO to initiator moles used, The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.
基金Funded by the National Natural Science Foundation of China(No.20376074) and the Special Funds for the Major State BasicResearch Projects (2003CCA01300)
文摘The preparation and electrocatalytic activity of polyaniline-poly （ propylene oxide ） （ PAN-PPO ） modified by Pt particles （ Pt/ PAN-PPO ） were investigated. Pt/ PAN-PPO was characterized by scanning electron microscopy （SEM） and energy dispersive spectroscopy （ EDS ）. Pt particles on PAN-PPO were in the nanometer range, and dispersed in a three-dimensional distribution on the surface of PAN-PPO film. Compared with polyaniline and glassy carbon modified with Pt particles under the same conditions, Pt/PAN-PPO exhibited a high electrocatalytic activity for lysine oxidation.
基金Supported by the National Natural Science Foundation of China (No. 29873014) and the Key Disciplinary Foundation of Shanghai.
文摘A series of ethylene oxide (EO)-propylene oxide (PO) randomco-polymers (EOPO) were used to form aqueous two-phase systems (ATPS)with ammonium sulfate. Effects of EOPO's properties on the phaseseparation behaviors and on the partition of cephalexin and7-aminodesacetoxicephalosporanic acid (7-ADCA) in ATPS wereinvestigated. Both the molar mass and molar ratio of EO to PO of EOPOcould greatly influence partition behaviors of cephalexin and 7-ADCAas well as the binodal curve of ATPS.
基金Supported by the National Natural Science Foundation of China(Nos.20704036, Key Program 20434020)the State Basic Research Projects of China(No.2005CB623802)
文摘The ring-opening copolymerization of adipic anhydride with propylene oxide was carried out with yttrium triflates as a catalyst. Poly（propylene adipate） could be synthesized by controlling the copolymerization conditions. The copolymerization procedure was tracked by ^1H NMR analyses.
文摘The copolymerization kinetics of ethylene oxide and propylene oxide in an atomizing-circulation reactorunder semi-continuous operation is studied which is of great importance for molecular designation. The kineticparameters are obtained by numerical optimization of the kinetic model.
基金Project (No. 2004C31058) supported by the Zhejiang ProvincialS&T Programme of China
文摘In this work, the surface activity of block copolymer nonionic surfactants (RPE) has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (Γ), surface area demand per molecule (A), surface tension at CMC (γCMC). A linear decrease of ln[CMC] vs number of oxypropylene units in copolymer molecule was observed. The change in the work of cohesion per oxypropylene group when passing from molecular into micellar state, calculated from the Shinoda equation, was 0.43kT for the studied compounds.
文摘In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom transfer radical polymerization(ATRP).The target products were confirmed by GPC and1H NMR.This well-defined copolymer can supply a promising material as drug and gene carriers and protective materials.
基金Supported by the National Natural Science Foundation of China(No.20973065)the Fund of Basic Research in Natural Science Issued by Shanghai Municipal Committee of Science+4 种基金 China(No.08dj1400100)the Shanghai Leading Project China (No.B409)the Foundation of Outstanding Young Talent in University of Anhui Province China No.2010SQRL042)
文摘The electrocatalytic synthesis of propylene carbonate（PC） from CO2 and propylene oxide（PO） was studied under mild conditions（PCO2=1.01×105 Pa, t=25 ℃）. Influences of solvents, supporting electrolytes, the passed charge, the nature of electrodes and the current density（j） on the yield of PC were investigated to optimize the electrolytic conditions, with the maximal yield to be 46.2%, the selectivity of propylene carbonate is 100%. The reduction of propylene oxide in the absence and presence of CO2 was examined by cyclic voltammetry. The mechanism of the reaction initiated by the synergistic effect of halides ions of supporting electrolytes with nucleophilicity and the metal ions from scarification anode with Lewis acid acidity was proposed on the basis of our results.
文摘Incorporation of strontium into V-Mo alumina-supported catalyst enhanced its performance (increased conversion and selectivity,decreased reducibility and improved stability) in propane oxydehydrogenation to propylene.12.5% Sr loading was shown to be the optimum content to the V-Mo catalyst.The results were supported by various characterization techniques,namely,BET,XRD,SEM,FTIR and TPD.
