Effect of operating conditions on dynamic crystallization of ethylene/1-octene copolymers

Abstract

Dynamic crystallization (DC) is a new characterization technique for measuring the chemical composition distribution (CCD) of semicrystalline copolymers. This technique fractionates polymers based on chain crystallizabilities under a constant cooling rate; a solvent is also fed through the column at a constant flow rate during the crystallization to enhance the physical separation of the polymer fractions. In this work, a DC model for ethylene/1-olefin copolymers on the basis of population balance, crystallization kinetics, and axial dispersion is proposed. This model is found to describe the experimental DC profiles of an ethylene/1-octene copolymer at various operation conditions very well. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.