Initiator systems resulting from the combination of cyclopentadienyltitanium trichloride (CpTiCl3), ethylaluminium dichloride (EtAlCl2) with and without methylaluminoxane (MAO), were used to initiate styrene (S) homopolymerization and S/1-alkene copolymerization. The CpTiCl3-EtAlCl2 system turned out to be an effective initiator of styrene homopolymerization as well as of styrene/1-decene (S/1-C10H20) and styrene/1-hexadecene (S/1-C16H32) copolymerization. Both S/1-C10H20 and S/1-C16H32 copolymers obtained from various S/1-alkene molar ratios in the initial feed contained variable amounts of boiling-butanone-insoluble product which was a S/1-alkene copolymer according to NMR and DSC analyses. The copolymers obtained showed Tg values which decrease as the proportion of 1-alkene in the initial feed increases