Interface Modification And Properties Of Carbon Nanotube/polypropylene Composites

One popular sort of engineering plastics,polypropylene(PP)is featured with excellent physical properties,outstanding mechanical performance,facile processability,as well as cost efficiency.Nevertheless,its practical application might be much restricted given such shortcomings as low temperature brittleness.Despite the recognized excellent performance of carbon nanotubes(CNTs),they are prone to agglomeration due to the large specific surface area and high surface energy.Also,the nonpolar properties of CNTs make them hardly compatible with polymers as manifested by the poor interface between the two components.Aiming at an improved compatibility between multi-walled carbon nanotubes(MWNTs)and polypropylene(PP),we report herein a practical strategy for the modification of MWNTs and subsequent fabrication into PP-g-MWNTs.The morphology of as-obtained PP-g-MWNTs was observed by scanning electron microscopy(SEM)and transmission electron microscopy(TEM),while their elemental composition and bond structures were characterized via Fourier transform infrared(FTIR)and(XPS).X-ray diffraction was further employed for crystallographic analyses.We also mainly studied the effects of PP-g-MWNTs on the mechanical and thermal properties of PP composites and interface enhancement mechanism.The mechanical results indicate that the mechanical properties of PP-g-MWNTs/PP composites can be greatly improved when the PP-g-MWNTs loading reach 0.50 wt.%.Performance comparison between the PP-gMWNTs samples and the undecorated ones was established based on dynamic mechanical analysis(DMA),differential scanning calorimetry(DSC),and thermal gravimetric analysis(TGA).the results show that the composites show that the PP composites with PP-g-MWNTs exhibit higher thermal stability and heat resistance than the pure PP.PP-gMWNTs with the percent grafting of 24 wt% was obtained in this thesis.At the same time,the electrical conductivity of composites increases with the increase of PP-g-MWNTs addition amount.In other words,the conductivity of the composite became increasingly better.This paper will provide a novel route to design low modulus elastic interface layer and prepare high toughness,and carbon nanotube composites with excellent mechanical properties.