Functional Group Containing Copolymers Prepared by the Ziegler-Natta Process

A novel method for the preparation of functional polyolefin copolymers by the Ziegler- Natta process using organoborane monomers is presented. B-5-Hexenyl-9-BBN (BBN = borabicyclo[3.3.1]nonane) and 1-octene were copolymerized and further oxidized to poly(octene-co-hexenol). The reactivity of the borane monomer was found to be only slightly lower than that of 1-octene, thus enabling the synthesis of copolymers with a wide range of composition. The comparison of the GPC profiles from the UV and RI detectors established the homogeneity of the copolymers. The same results were also concluded from the DSC studies. A single T_g, which increased with the hydroxyl content, was observed. Although the molecular weights of the copolymers were found to be high, their GPC profiles suggested a lowering of molecular weights with increasing borane monomer in the feed. To establish the effect of a trialkylborane on the polymerization, 1-octene was polymerized with/without an equimolar amount of Et₃B, and no significant effect on the molecular weight was observed.