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Acrylonitrile (AN) and itaconic acid (IA) were used to synthesize UHMWPAN by aqueous suspension method with 2,2’-azobisisobutyronitrile (AIBN) as the initiator and polyvinylalcohol (PVA) as the disperser at different temperatures (55°C~75°C) for different timings (1.0h~3.0h). The usage amounts of AN, IA, AIBN and PVA were also technical polymerization parameters used to obtain the optimal polymerization process. We found that the conversion and the viscosity average molecular weight both achieved the optimum levels when the conditions were as follows: the total monomer concentration (21wt%), the monomer ratio (AN: IA=98:2), the usage amount of the initiator (AIBN, 0.01wt%), the usage amount of the disperser (PVA, 0.1wt%), the polymerization temperature (70°C) and the polymerization time (2h).

The extraction equilibrium of four rare earth ions (REn+, n = 3 or 4) was investigated in ionic liquid (IL) extraction system using 1-butyl-3-methyl-imidazolium hexafluorophosphate ([Bmim]PF6) ionic liquid as extraction solvent and 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP, HP) as extractant. The extraction percentage could be higher than 99%. The extracted species in the REn+-[Bmim]PF6-HP system was neutral REPn (n = 3 or 4) and complete recovery of REn+ extracted into [Bmim]PF6 can be achieved using diluent HCl as stripping agent. [Bmim]PF6 can be recycled in the experiment. The extraction equilibrium constants and the pH1/2 values of four REs and their separation factors between adjacent rare earths were estimated and comparatively studied.

The effects of ultra high molecular weight Polyacrylonitrile (UHMW-PAN) on the rheological behavior of PAN/DMSO solution have been investigated using a cone-plate rheometer in this work. The rheological behavior was characterized by steady shear and oscillation test It is observed from the measurements that, the rheological behavior of the polymer mixture of UHMW-PAN and AMW-PAN makes a difference to the AMW-PAN solution due to macromolecular entanglements, the viscosities of the solutions decreased with the rising of shear rate, shear viscosity rise with the increase of the molecular weight of the UHMW-PAN. For dynamic experiments, a steady increase of both and with the increase of oscillation frequency and molecular weight of UHMW-PAN was seen for all samples. The and increase with the decrease of the temperature or with the increase of the contents of the UHMW-PAN.