One-step synthesis of hollow spherical polyethylene by dispersion polymerization.

Hollow polyethylene spheres were achieved from solution-based ɑ-diimine nickel catalyst system with morphological controllable one-step synthesis. • Homogenous ɑ- diimine nickel complexes often produce bulk viscous polyethylene. • Spherical hollow polyethylene produced by coordination dispersion polymerization. • Tri-nuclear nickel complex show high activity for ethylene polymerization. In this paper, ɑ-diimine nickel catalyst without immobilization was successfully used for one-step synthesis of spherical hollow polyethylene particles at mild condition (1.0 MPa, 25 °C) by conducting coordination dispersion polymerization. It was found 2-methyl-2-pentanol (MP) played a key role in the formation of the unusual hollow particular morphology. By varying the addition amount of MP, changing the bulky groups of alkyl aluminum, and adjusting the concentration of nickel catalyst, the particle size was finely tuned. A plausible mechanism was proposed to interpret the formation of these polyethylene hollow particles. [ABSTRACT FROM AUTHOR]