A Novel Polymer Supported Catalyst for Preparation of Sydiopolystyrene

Poly (styrene-co-acrylonitrile) supported TiCl4 was prepared and characterized. IR analysis shows that the absorption of the acronitrile group shifted from 2233cm-1 to 2277cm-1 after its coordination to TiCl4. It is found that this catalyst shows a much higher catalytic activity than that of TiCl4 in the preparation of sydiopolystyrene, especially, it can be used to prepare a styrene rich poly (styrene-co-ethylene), the resulted poly (styrene-co-ethylene) is a crystalline polymer shown a Tm much lower than that of a homo sydiopolystyrene. The molecular simulation result shows that the coordinated metal in the polymer catalyst is more cationic, probably due to an electron withdraw group coordinated to the central metal. This result can help us to understand that the polymer catalyst is more active and there is less cocatalyst MAO was used in the polymerisation process. Based on the results both of the experiment and the molecular simulation, we can give a conclusion that the polymer backbone stabilized the central metal Ti and make it difficulty to be reduced to a TiII complex, and the later shows no activity in the polymerisation. The stabilization is from the coordination of the polymer backbone and not due to an electron donor ligand which is in a normal metallocene.