A NEW RARE-EARTH COORDINATION CATALYST FOR POLYMERIZATION OF ACRYLONITRILE

Polymerization of acrylonitrile was carried out for the first time usi ng the rare-earth coordination catalysts composed of rare-earth 2-ethy l hexyl phosphonate [Ln(P-204)(3)], dibutylmagnesium [Mg(Bu-n)(2)], an d N,N,N',N'-tetramethyl ethylene diamine (TMEDA, 1:6:6 molar ratio). T he new catalyst gives high molecular weight polyacrylonitrile in fairl y good yield. The triad tacticities of the polymers obtained increase with a decrease of polymerization temperature and mm content attains 0 .52 at -78 degrees C. (C) 1997 Elsevier Science Ltd.