KINETIC ASPECTS OF THE COPOLYMERIZATION BETWEEN ALPHA-OLEFINS AND BORANE MONOMER IN ZIEGLER-NATTA CATALYST

This paper focuses on the reactivity of a borane monomer, e.g., 5-hexenyl-9-BBN, in Ziegler-Natta copolymerization with alpha-olefins, e.g., propylene, 1-butene, and 1-octene. The monomer reactivities were studied by reactivity ratio, copolymer compositions during the reaction and copolymer microstructure. In general, the borane monomer can be effectively incorporated into polyolefins with controllable concentrations and locations. Due to the excellent stability of boranes to the catalyst and solubility of boranes in hydrocarbon solution, the borane monomer behaves as a high alpha-olefin monomer in Ziegler-Natta polymerization. In turn, the trialkylboranes in copolymers are easily converted to various functional groups under homogeneous or heterogeneous reaction conditions. In the cases of polypropylene and poly(1-butene), the chemistry not only achieves functionalization but also preserves most useful physical properties, such as crystallinity and thermal stability, of the isotactic homopolymers.