Shear enhanced interfacial interaction between carbon nanotubes and polyethylene and formation of nanohybrid shish-kebabs

In this work, raw multiwalled carbon nanotubes (MWNTs) without any pre-treatment were blended with linear low density polyethylene (LLDPE), then molded via a so-called Dynamic Packing Injection Molding (DPIM) technique, in which oscillatory shear was exerted on the prepared composites during the stage of cooling solidification. The injection molded samples were extracted by xylene to remove LLDPE, and the remained MWNTs were collected and characterized. Shear enhanced interfacial adhesion between MWNTs and LLDPE was confirmed by dissolution experiment and Fourier transform infrared. The former a longer mixing time in xylene for remained MWNTs compared with raw MWNTs, while in the latter an increased intensity of characteristic LLDPE peak for MWNTs subjected to dynamic packing injection molding. More importantly, SEM images showed a formation of MWNTs/LLDPE nanohybrid shish-kebab, in which MWNTs served as shish, and LLDPE lamellae as kebab and periodically decorated on MWNTs. A simultaneously improved tensile strength and elongation of LLDPE have been achieved by adding the LLDPE-decorated MWNTs. Our work provides a new way for the modification of MWNTs, particularly a convenient way for the enhancement of interfacial adhesion in polymer/MWNT composites via realistic molding processing. (C) 2008 Elsevier Ltd. All rights reserved.