Noncovalent compatibilization of polypropylene/MWCNT composites using an amino-pyridine grafted polypropylene matrix

Abstract

Polypropylene (PP)/multiwalled carbon nanotube (MWCNT) composites are prepared by implementing noncovalent compatibilization. The compatibilization method involves PP matrix functionalization with pyridine (Py) aromatic moieties, which are capable of π–π interaction with MWCNT sidewalls. Imaging revealed that the addition of 25 wt% of PP-g-Py to neat PP is capable of drastically reducing nanotube aggregate size and amount, compared to a matrix containing the equivalent amount of a maleated PP (PP-g-MA). Raman spectroscopy confirms improved polymer/nanotube interaction with the PP-g-Py matrix. The electrical percolation threshold appears at a MWCNT loading of approximately 1.2 wt%, and the maximum value of the electrical conductivity achieved is 10−2 S/m, irrespective of the functionalization procedure. The modulus of the composites is improved with the addition of MWCNTs. Furthermore, composites functionalized with Py display significant improvements in composite ductility compared with their maleated counterparts because of the improved filler dispersion. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers