Old newsprint/polypropylene nanocomposites using carbon nanotube: Preparation and characterization

Abstract

The preparation and characterization of old newsprint (ONP)/polypropylene (PP) nanocomposites are presented in this paper. The effect of multi-walled carbon nanotube (MWCNT) as reinforcing agent on the mechanical, physical and morphological properties was also investigated. In order to increase the interphase adhesion, polypropylene grafted with maleic anhydride (MAPP) was added as a coupling agent to all the composites studied. In the sample preparation, MWCNT dosage (0,0.5,2.5 and 3.5wt%) and MAPP content (0,3wt%) were used as variable factors. The morphology of the specimens was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The results of strength measurement indicated that when 1.5wt% MWCNT was added, Izod impact strength improved significantly while tensile and flexural properties were reached the maximum when 2.5wt% MWCNT were used. Both mechanical and physical properties were improved when 3wt% MAPP was applied. The optimum condition for enhancing physical and mechanical properties was 3wt% MAPP and 2.5wt% MWCNT. SEM results have shown that the treatment of composites with 3wt% MAPP, promotes better fiber–matrix interaction, resulting in a few numbers of pull-out traces and smoother surfaces. MWCNT can fill the voids of composites as well as addition of MAPP made strong interaction between the ONP and matrix. Besides, TEM micrographs showed that at high level of MWCNT loading (3.5wt%) increased population of MWCNT leads to agglomeration and stress transfer gets blocked.