Polymer materials based on ethylene copolymers with substituted norbornene

The copolymers of ethylene with 5-ethylidene-2-norbornene containing 10–65% of the cyclic comonomer have been prepared with the use of three ansa -metallocene catalysts, namely, Et[Ind] 2 ZrCl 2 -methylaluminoxane, Et[IndH 4 ] 2 ZrCl 2 -methylaluminoxane, and Me 2 Si[Ind] 2 ZrCl 2 -methylaluminoxane. Side groups >C=CH-CH 3 capable of participation in the ozonolysis reaction have been incorporated into polymer chains via the copolymerization of ethylene with the cyclic comonomer. As evidenced by DSC, and X-ray diffraction, and very cold neutron scattering measurements of the supramolecular structure of the copolymers, the enrichment of the copolymer with the cyclic comonomer causes transformation of the ethylene-5-ethylidene-2-norbornene copolymer from the semicrystalline state to the amorphous state. This effect is accompanied by an increase in the density and optical transparency of the material and a rise in its glass transition temperature. Among the copolymers under study, the highest T g (83°C) is exhibited by the copolymer synthesized with the Et[Ind] 2 ZrCl 2 -methylaluminoxane catalyst and containing 30 mol % 5-ethylidene-2-norbornene.