H-2-D-2 EXCHANGE-REACTION WITH MGCL2-SUPPORTED ZIEGLER CATALYST BY STOPPED-FLOW METHOD

The effect of hydrogen on the chain transfer reaction in the initial s tage of propene polymerization with MgCl2-supported Ziegler catalyst w as studied through H-2-D-2 exchange reaction using the stopped-flow me thod. When the exchange reaction was carried out with various catalyst components at room temperature for 5 min, HD was produced only in cas e of using the catalyst with Al(C2H5)(3). In case of the stopped-flow method (reaction time ca. 0.1 s), the catalyst without pre-treatment w ith Al(C2H5)(3) showed no activity for the H-2-D-2 exchange reaction ( no HD produced), while the catalyst with pre-treatment had exchange ac tivity. As the chain transfer activity of H-2 in propene polymerizatio n shows the same tendency, it is evident that chain transfer with H-2 occurs via atomic hydrogen generated on the pre-treated catalyst.