Vinyl-type polymerization of norbornene has been carried out with half-titanocene/MAO catalysts. It was found that the Cp(cyclopentadienyl)-bearing titanocene catalysts afford the polynorbornene at much higher yield...Vinyl-type polymerization of norbornene has been carried out with half-titanocene/MAO catalysts. It was found that the Cp(cyclopentadienyl)-bearing titanocene catalysts afford the polynorbornene at much higher yield than the related Cppentamethylcyclopentadienyl-bearing one. On the other hand, substitution of —OR ligand for chlorine at the Cp-bearing compound causes remarkbaly increase in catalytic activity. The optimum temperature for the polymerization is 60 ℃. All the polynorbornenes obtained with CpTi(OCH2Ph)3/MAO catalyst are soluble in the organic solvents such as cyclohexane and monochlorobenzene. The FTIR and 13C NMR spectra indicate that the polynorbornene obtained is vinyl-type polymer and has low stereo-regularity.展开更多
The new chelate resins, abbreviated as PNBMZs and PBBMZs based on epoxide polymer, were synthesized by polycondensation of N,N-diglycidyl-4-glycidyloxyaniline or 1,4-bis(2,3-epoxypropyl)benzene with the primary amin...The new chelate resins, abbreviated as PNBMZs and PBBMZs based on epoxide polymer, were synthesized by polycondensation of N,N-diglycidyl-4-glycidyloxyaniline or 1,4-bis(2,3-epoxypropyl)benzene with the primary amine group of 1,3-bis(benzimidazol-2yl)propylamine (BBPAH). The ion exchangers contain 2.71-3.23 mmol of the ligand contents per gram of the resin. Batch extraction capacities were determined for the metal chloride salts in buffer solutions in the pH range from -1 to 6.0. The chelate resins were very selective for Cu^2+, Zn^2+, Cd^2+ in the presence of other divalent transition metal ions. The maximum uptake capacities of PNBMZ (synthetic molar ratio = 1:1.5) under non-competitive condition were found to be 0.94 mmol/g for Cu^2+ at pH = 2, 1.3 mmol/g for Cd^2+ at pH = 1 and 1.75 mmol/g for Zn^2+ at pH = -1 respectively. While in the case of PBBMZ, it was 1.39 mmol/g for Cd〉 at pH = 1. The metal-uptake behaviors for both of them showed strong pH dependence, and their extraction capacities increase with decreasing pH. The uptake of Cu^2+ by the resin PNBMZs at pH = 1 was found to be rather fast with t1/2 = 18 min. Metal-uptake experiments under competitive conditions also confirm that the chelate resins have a high selectivity for Cu^2+, Zn^2+, Cd^2+ and the contrary pH dependence.展开更多
文摘Vinyl-type polymerization of norbornene has been carried out with half-titanocene/MAO catalysts. It was found that the Cp(cyclopentadienyl)-bearing titanocene catalysts afford the polynorbornene at much higher yield than the related Cppentamethylcyclopentadienyl-bearing one. On the other hand, substitution of —OR ligand for chlorine at the Cp-bearing compound causes remarkbaly increase in catalytic activity. The optimum temperature for the polymerization is 60 ℃. All the polynorbornenes obtained with CpTi(OCH2Ph)3/MAO catalyst are soluble in the organic solvents such as cyclohexane and monochlorobenzene. The FTIR and 13C NMR spectra indicate that the polynorbornene obtained is vinyl-type polymer and has low stereo-regularity.
文摘The new chelate resins, abbreviated as PNBMZs and PBBMZs based on epoxide polymer, were synthesized by polycondensation of N,N-diglycidyl-4-glycidyloxyaniline or 1,4-bis(2,3-epoxypropyl)benzene with the primary amine group of 1,3-bis(benzimidazol-2yl)propylamine (BBPAH). The ion exchangers contain 2.71-3.23 mmol of the ligand contents per gram of the resin. Batch extraction capacities were determined for the metal chloride salts in buffer solutions in the pH range from -1 to 6.0. The chelate resins were very selective for Cu^2+, Zn^2+, Cd^2+ in the presence of other divalent transition metal ions. The maximum uptake capacities of PNBMZ (synthetic molar ratio = 1:1.5) under non-competitive condition were found to be 0.94 mmol/g for Cu^2+ at pH = 2, 1.3 mmol/g for Cd^2+ at pH = 1 and 1.75 mmol/g for Zn^2+ at pH = -1 respectively. While in the case of PBBMZ, it was 1.39 mmol/g for Cd〉 at pH = 1. The metal-uptake behaviors for both of them showed strong pH dependence, and their extraction capacities increase with decreasing pH. The uptake of Cu^2+ by the resin PNBMZs at pH = 1 was found to be rather fast with t1/2 = 18 min. Metal-uptake experiments under competitive conditions also confirm that the chelate resins have a high selectivity for Cu^2+, Zn^2+, Cd^2+ and the contrary pH dependence.