Polyolefins functionalization by copolymerization of ethylene (propylene) with substituted norbornene

A number of new copolymers of ethylene (propylene) and 5-ethylidene-2-norbornene (EN) containing 5-62 mol. % of the cyclic comonomer units in the main chain have been synthesized by employing of three ansa-metallocene catalytic systems, namely: Et[Ind]2ZrCl2/methylalumoxane, Et[IndH 4 ] 2 ZrCl 2 /methylalumoxane or Me2Si[Ind]2ZrCl2/methylalumoxane. In this way side >C=CH-CH 3 groups in the range up to 7 10 -3 mol/g were incorporated into a structure of polyolefin chain. As it was found by IR-spectroscopy, the side ethylidene groups of poly(ethylene-co-5-ethylidene-2-norbornene) were susceptible to ozonolysis reactions and converted into the polar carbonylic groups. According to DSC, X-ray diffraction and very cold neutrons scattering (VCN) data, enrichment of poly(ethylene-co-5-ethylidene-2-norbornene) with EN units has lead to eventual transformation of the studied copolymers from a partly crystalline state to a fully amorphous one. With the growing cyclic comonomer partial content the copolymers have exhibited progressively better optical transparency and higher glass transition temperatures (up to 85 °C); they are characterized by a high density (d > 1000 kg/m 3 ).