Nano-sized polyacrylonitrile （PAN） particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emu...Nano-sized polyacrylonitrile （PAN） particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emulsion polymerization was studied at varying concentrations of the initiator, monomer, complex and solvent over a temperature range of 30-70℃. The overall activation energy （Ea, 49.79 kJ/mol）, energy of dissociation of initiator （Ed, 82.68 kJ/mol）, number of micelles （0.163 × 10^18） and the viscosity average molecular weight of the polymer were computed. The distribution of particle sizes was determined by transmission electron microscopy （TEM）. It was found that the oil-in-water polymerization was stabilized by the presence of the CoCl2/EDTA in situ complex reducing the particle size into the nano order. The average diameters of PAN nano particles, obtained by TEM, were in the range of 50-150 nm at the maximum conversion. The experimental particle size was mainly dependent on the concentration of the complex and temperature.展开更多
文摘Nano-sized polyacrylonitrile （PAN） particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emulsion polymerization was studied at varying concentrations of the initiator, monomer, complex and solvent over a temperature range of 30-70℃. The overall activation energy （Ea, 49.79 kJ/mol）, energy of dissociation of initiator （Ed, 82.68 kJ/mol）, number of micelles （0.163 × 10^18） and the viscosity average molecular weight of the polymer were computed. The distribution of particle sizes was determined by transmission electron microscopy （TEM）. It was found that the oil-in-water polymerization was stabilized by the presence of the CoCl2/EDTA in situ complex reducing the particle size into the nano order. The average diameters of PAN nano particles, obtained by TEM, were in the range of 50-150 nm at the maximum conversion. The experimental particle size was mainly dependent on the concentration of the complex and temperature.
