Polymerization of styrene catalyzed by rare earth Schiff base complexes

Abstract

The rare earth Schiff base complex Nd(H₂Salen)₂Cl₃2C₂H₅OH was synthesized by a simple and convenient method and characterized by IR and elemental analysis. The catalyst system composed of Nd(H₂Salen)₂Cl₃2C₂H₅OH/Al(i-Bu)₃/CCl₄ is effective for the polymerization of styrene (St). The optimum conditions are as follows: [St]/[Nd] = 1000, [CCl₄]/[Nd] = 9, [Al]/[Nd] = 30, and polymerization at 50°C for 20 h. The resulting polystyrene was characterized by NMR and GPC. The results of NMR show that the polymer obtained had a stereoregularity with 52.3% isotacticity and 47.7% syndiotacticity without any random structure.

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