Preparation of Polyethylene Nanocomposites Based on Polyethylene Grafted Exfoliated α-Zirconium Phosphate

Abstract

Polymer nanocomposites containing well-exfoliated nanoplatelets have been shown to possess greatly enhanced physical and mechanical properties. However, it is still a significant challenge to achieve adequate exfoliation of 2D nanoplatelets in polyolefin matrices due to poor compatibility and associated entropic penalty between 2D inorganic filler and nonpolar polyolefin matrices. Grafting polyolefin chains onto the surfaces of an already exfoliated nanoplatelet is a simple, yet effective solution to this problem. The grafted polyolefin chains on the nanoplatelets can entangle and cocrystallize with the polyolefin matrix, preventing agglomeration. In this study, polyethylene (PE) grafted α-zirconium phosphate (ZrP), ZrP-g-PE, was prepared and blended with the PE matrix. The graft density of ZrP-g-PE was designed to maintain ZrP exfoliation during subsequent blending with the PE matrix. It was found that PE confined crystallization formed in ZrP-g-PE, resulting in the formation of PE crystal orientation perpendicular to the ZrP nanoplatelets. The usefulness of this study for preparation of high-performance polyolefin nanocomposites is discussed.