| Abstract: | Copolymerization of different amounts of styrene (St) and 4‐methylstyrene (MSt) using Cp*Ti(OBu)3/MAO/TIBA catalyst was performed in bulk state under hydrogen atmosphere. With out the participation of a reaction solvent, polymerization proceeded well with better yield as compared to those with toluene or cyclohexane as reaction solvent. The sharp peaks in the 13C NMR spectra indicate that both the St and MSt units in the copolymers are co‐syndiotactic in nature. The reactivity ratio evaluated from a Fineman‐Ross plot suggests a better reactivity of MSt than St monomers. Experiments also indicate that the decrease of Mn and Mw, and the broadening of molecular weight distribution were accompanied by the higher hydrogen pressure employed in the polymerization stage, a result attributed to the chain transfer reaction promoted by the hydrogen gas. |
