Epitaxial Crystallization of Precisely Methyl-Substituted Polyethylene Induced by Carbon Nanotubes and Graphene

Abstract

How large of a substituent/branch a polyethylene possesses that can still be induced by nanofillers to form ordered chain structures is interesting, but uncertain. To solve this problem, precisely methyl-substituted polyethylene (PE21M) was chosen as a model to prepare its one-dimensional and two-dimensional nanocomposites with carbon nanotubes (CNTs) and graphene via solution crystallization. It is shown that kebab-like and rod-like nanofiller-induced crystals were separately observed on the surfaces of CNTs and graphene and the density of rod-like crystals is significantly less than kebab-like ones. The results of differential scanning calorimetry (DSC) and X-ray diffraction (XRD) reveal that CNTs and graphene cannot induce polymers with the substituent volume greater than, or equal to, 2 Å (methyl) to form ordered lattice structure, but CNTs exhibit the better nucleation effect, providing us with guidance to manipulate the physical performance of polymer composites on the basis of the size of the substituent and the type of nanofiller.

Keywords

• PE21M
• carbonaceous nanofiller
• epitaxial crystallization