Preparation of Polar Ethylene-Norbornene Copolymers by Metallocene Terpolymerization with Triisobutylaluminium-Protected But-3-en-1-ol.

But-3-en-1-ol has been pre-protected by triisobutylaluminium and terpolymerized with ethylene and norbornene by rac-[Et(Ind)(2) ]ZrCl(2) /MAO catalysts. The strong polarity of diisobutyl(but-3-en-1-oxy)aluminum causes a slight reduction in the catalyst activity and yields a small fraction of crystallinity. The but-3-en-1-ol content in the terpolymer is as high as 3.2% and can be readily adjusted by varying the reaction conditions. When the norbornene/ethylene ratio is over 10, the norbornene incorporation efficiency is not affected by the polar monomer and is close to that of the copolymerization. Similar to the ethylene/norbornene copolymers, the thermal properties of the obtained terpolymers are mainly determined by their norbornene contents.