FRACTIONATED CRYSTALLIZATION OF HDPE IN PS/POE/HDPE/SBS BLENDS

The fractionated crystallization behavior of the minor dispersed HDPE phase in PS/POE/HDPE/SBS quaternaryblends was investigated by differential scanning calorimetry (DSC).Interestingly,we found that the fractionated crystallization behavior of HDPE was molecular weight dependent.At a fixed composition,HDPE with lower molecular weight showed more obvious fractionated crystallization behavior than HDPE with higher molecular weight.This was ascribed to a finer dispersion of HDPE with lower molecular weight,as evidenced by SEM observations.The fractionated crystallization behavior of HDPE in the blends became less obvious with increasing of its content,due to a change of phase morphology from droplet to co-continuous structure.Correspondingly,a change of tensile toughness of the blends from brittle to ductile mode was observed.