writer：Wu Linbo, Li Bogeng*, Cao Kun, Li Baofang
keywords：Rare earth catalyst,Catalyst preparation,Polymerization,Styrene
source：期刊
specific source：European Polymer Journal, 37(10): 2105-2110, 2001.10
Issue time：2001年

The ternary catalyst system neodymium phosphate/di-n-butyl magnesium triethyl aluminum ccomplex/hexamethyl phosphoramide(Nd(P₂₀₄)₃/MgBu_2. AlEt₃/HMPA) for the polymerization of styrene was examined. The effects of the addition order of each component , the aging time and temperature and the presence of a small amount of styrene during the preparation of the catalyst system on the acctivity of the catalyst system and the molecular weight of the resultant polymers were investigated . A stable and homogeneous catalyst system which produces polystyrene with narrow molecular weight distribution can be prepared by an alkylation reaction of  Nd(P₂₀₄)₃  with  MgBu_2. AlEt₃  at  ambient temperature followed by the addition of HMPA . An introduction of a small amount of  styrene during the  preparation of  the catalyst can further improve their stability.