The copolymerization of ethylene with dieyclopentadiene （DCP） in the presence of a constrained geometry tetramethylcyclopentadi-enyl-phenoxytitanium catalyst [ 2,4-＇ Bu2-6-（ 2,3,4,5-Me4 -Cp ） -PhO ] TICl2, combined with AI（ iBu）3/Ph3C^＋ B（ CsF5 ）4^- cocatalyst system was studied. The copolymers that were formed were characterized by ＇ H and ,3 C NMR, differential scanning calorimetry （ DSC）, SEM, and X-ray diffraction （XRD） analyses. The re- suits of the analysis indicate that the copolymers of ethylene with dicyclopentadiene are amorphous and display two or more melting temperatures in their DSC diagrams. Moreover, the morphologies of the copolymers are quite different from that of polyethylenes.
