Solution copolymerization of ethylene with α-olefin by vanadium catalyst

Summary

Copolymerization of ethylene with an α-olefin, i.e. propylene, butene-1 and 4-methyl-pentene-1(4-MP-1), was carried out by vanadium catalyst prepared by treating VOCl₃ with (n-C₈H₁₇)₃Al in decane in combination with Et₃Al and CHCl₃. The copolymerization system was homogeneous at a temperature as high as 170 °C. It has been revealed that the monomer insertion reaction of irregular direction, i.e. the insertion giving rise to the growing end of secondary alkyl / catalyst bond, occurs occasionally at the propagation of the α-olefin comonomer. The irregular insertion takes place most frequently with 4-MP-1. The chain transfer with hydrogen takes place more preferentially at the irregular propagation end in comparison with the regular one.