Removal of oligomers from substantially crystalline, alpha -olefin polymers

摘要

Disclosed is a method for removing oligomers from substantially crystalline, alpha -olefin polymer particles without having to melt the particles. The method comprises fluidizing a bed of the particles with a gas in which the oligomers are soluble, which bed is at a temperature at which the particles are not sticky, but at least lower molecular weight oligomers will evaporate therefrom, and maintaining the particles in the fluidized bed until a substantial portion of the oligomers have evaporated and have been removed from the bed by the fluidizing gas. By regulatng the bed temperature and the residence time of the particles in the bed the proportion and chain length of the oligomers removed can be controlled.