Polymerization of 2-allylnorbornane using Ziegler-Natta catalysts: copolymerization with ethylene

The copolymerization of ethylene with 2-allylnorbornane (2-ANB) was studied using Ziegler-Natta and homogeneous metallocene catalysts. The copolymers were characterized by IR, NMR, XRD, GPC, and thermal methods. It was found that the copolymers obtained using the TiCl4/TIBAL catalyst were heterogeneous and blocky in nature while those obtained using Cp2ZrC12/methylaluminoxane (MAO) were homogeneous and random in nature. A comparison between ethylene-2-ANB (norbornyl pendant) and ethylene-4-methyl-1-pentene (isopropyl pendant) copolymers led to the conclusion that both the isopropyl and norbornyl pendant give rise to a similar lowering in the values of ΔHf and Tm