Aqueous deposited copolymerization of acrylonitrile with ammonium itaconate under magnetic field

Copolymerization of acrylonitrile(AN) with ammonium itaconate (AIA) initiated by ammonium persulfate (APS) was investigated in deionized water at 60°C under magnetic field(MF). The values of monomer apparent reactivity ratios were calculated by Kelen-Tudos method and the conversion was also measured. It has been found that the polymer radical group with an AIA unit at the chain end is considerably more active in the presence of MF, the conversion of solution polymerization of AN in the presence of MF is higher at the same ratio of AN/AIA. The molecular weight distribution (MWD) is narrower than that prepared without MF because of the orientation of their spin moments under MF. moreover, the fluctuation of the lifetime of propagating AN macroradicals is smaller. It is clear that the crystallization degree of powder polyacrylonitrile (PAN) prepared with MF is higher than that PAN obtained without MF. For the attained fibers coming from the dope treated under MF, the thermal properties become more stable, which also affects on the mechanical properties of the resultant fibers.