Effect of nano SiO₂ content and surface treatmeat on the isothermal crystallization behavior of LLDPE filled was investigated by DSC method. Results show that the crystallization rate of the system firstly increases and then decreases with increase in nano SiO₂ content. The reason is that the adsorption of LLDPE chains on the filler surface plays a decisive role on the crystallization behavior when the nano SiO₂ content is lower, and the nucleation prevails when the nano-SiO₂ content is higher.Simultaneously, compared to the surface-treatment of coupling agents with same nano-SiO₂ content, the co-surface-treatment of coupling agents and dispersing agent
results in an increase in the thickness of surface filler adsorption layer and the compatibility between the matrix and filler, which lead to an obvious heterogeneous nucleation of filler and an increase in the crystallization rate of
matrix.