(Silver-poly(4-vinylpyridine))(Ag-P4VP) hybrid microgels were synthesized by γ-irradiation and surfactant-free emulsion polymerization in a single step.The effects of dose rate and the concentrations of isopropanol,s...(Silver-poly(4-vinylpyridine))(Ag-P4VP) hybrid microgels were synthesized by γ-irradiation and surfactant-free emulsion polymerization in a single step.The effects of dose rate and the concentrations of isopropanol,silver ion,N,N′-methylenebisacrylamide(Bis) and 4-vinylpyridine(4-VP) on the hybrid microgels were studied in detail via transmission electron microscopy(TEM),powder X-ray diffraction(XRD) or dynamic light scattering(DLS).The results indicated that the size of Ag nanoparticles in the hybrid microgels increased with the increase of Ag^+ or Bis concentration and with the decrease of dose rate or isopropanol concentration.When the dose rate was decreased,the phase state of Ag nanoparticles was gradually transformed from amorphous state to cubic crystalline state.Although the variety of the P4VP microgels’ size was more complex,it could also be easily adjusted by the above-mentioned conditions.展开更多
Polyethylene (PE) grafting 4-vinylpyridine copolymers has been produced as powders of different rushes by theirradiation method. After treatment with methylaluminoxane (MAO), the copolymers were used as supports for C...Polyethylene (PE) grafting 4-vinylpyridine copolymers has been produced as powders of different rushes by theirradiation method. After treatment with methylaluminoxane (MAO), the copolymers were used as supports for Cp_2ZrCl_2catalyst Results of X-ray photoelectron spectroscopy, Fourier transforms infrared spectroscopy, ultraviolet spectroscopy andscanning electron microscope measurements show that the catalytic sites have been linked through MAO on the PE-graft-4-vinylpyridine (PEVP). The percentages of grafting 4-vinylpyridine and supported Cp_2ZrCl_2 depend on the size ofpolyethylene powder. The smaller the polyethylene powder, the more percent of 4-vinylpyridine groups and Cp_2ZrCl_2 existon the polyethylene chains, and the PEVP-supported catalyst has a relatively high activity for ethylene polymerization.展开更多
The catalytic activity of poly（styrene-acrylic acid） （PSAA） supported neodymium chloride （NdCl3） complex for the copolymerization of styrene and 4-Vinylpyridine was studied. The influence of various factors, suc...The catalytic activity of poly（styrene-acrylic acid） （PSAA） supported neodymium chloride （NdCl3） complex for the copolymerization of styrene and 4-Vinylpyridine was studied. The influence of various factors, such as Al/Nd molar ratio, reaction time, macromolecular carder （PSAA）, and ratio of styrene to 4-vinypyridine （g/g）, on the copolymerization yield of styrene and 4-Vinylpyridine was investigated. The results showed that the copolymerization of polar monomers with olefins occurred efficiently and the catalytic activity of polymer-supported catalyst was higher than that of the similar small molecular catalysts. The activity of PSAA.Nd complex increased with in- creasing Al/Nd molar ratios and decreased with increasing polymerization time. The highest activity of PSAA＇Nd was observed at 120 min, and the highest yield was found at the ratio of styrene to 4-vinylpyridine of 4：2. DSC analysis presented that the resulted polymer had only one glass transition temperature, and showed very good thermal stability.展开更多
文摘(Silver-poly(4-vinylpyridine))(Ag-P4VP) hybrid microgels were synthesized by γ-irradiation and surfactant-free emulsion polymerization in a single step.The effects of dose rate and the concentrations of isopropanol,silver ion,N,N′-methylenebisacrylamide(Bis) and 4-vinylpyridine(4-VP) on the hybrid microgels were studied in detail via transmission electron microscopy(TEM),powder X-ray diffraction(XRD) or dynamic light scattering(DLS).The results indicated that the size of Ag nanoparticles in the hybrid microgels increased with the increase of Ag^+ or Bis concentration and with the decrease of dose rate or isopropanol concentration.When the dose rate was decreased,the phase state of Ag nanoparticles was gradually transformed from amorphous state to cubic crystalline state.Although the variety of the P4VP microgels’ size was more complex,it could also be easily adjusted by the above-mentioned conditions.
基金National Natural Science Foundation of China (No. 20272062)
文摘Polyethylene (PE) grafting 4-vinylpyridine copolymers has been produced as powders of different rushes by theirradiation method. After treatment with methylaluminoxane (MAO), the copolymers were used as supports for Cp_2ZrCl_2catalyst Results of X-ray photoelectron spectroscopy, Fourier transforms infrared spectroscopy, ultraviolet spectroscopy andscanning electron microscope measurements show that the catalytic sites have been linked through MAO on the PE-graft-4-vinylpyridine (PEVP). The percentages of grafting 4-vinylpyridine and supported Cp_2ZrCl_2 depend on the size ofpolyethylene powder. The smaller the polyethylene powder, the more percent of 4-vinylpyridine groups and Cp_2ZrCl_2 existon the polyethylene chains, and the PEVP-supported catalyst has a relatively high activity for ethylene polymerization.
基金Science Technology Foundation of Jilin Province (200223)
文摘The catalytic activity of poly（styrene-acrylic acid） （PSAA） supported neodymium chloride （NdCl3） complex for the copolymerization of styrene and 4-Vinylpyridine was studied. The influence of various factors, such as Al/Nd molar ratio, reaction time, macromolecular carder （PSAA）, and ratio of styrene to 4-vinypyridine （g/g）, on the copolymerization yield of styrene and 4-Vinylpyridine was investigated. The results showed that the copolymerization of polar monomers with olefins occurred efficiently and the catalytic activity of polymer-supported catalyst was higher than that of the similar small molecular catalysts. The activity of PSAA.Nd complex increased with in- creasing Al/Nd molar ratios and decreased with increasing polymerization time. The highest activity of PSAA＇Nd was observed at 120 min, and the highest yield was found at the ratio of styrene to 4-vinylpyridine of 4：2. DSC analysis presented that the resulted polymer had only one glass transition temperature, and showed very good thermal stability.
