Dispersion and mechanical properties of polypropylene/multiwall carbon nanotubes composites obtained via dynamic packing injection molding

Abstract

In this article, polypropylene (PP)/multiwall carbon nanotubes (MWNTs) composites were prepared through dynamic packing injection molding, in which the oscillatory shear was exerted on the molten composite during packing and solidification stage of injection-molding. A simultaneous increase of tensile strength and impact strength has been achieved for PP/MWNTs composites containing only 0.6 wt % MWNTs. Particularly, the impact strength was found increased by almost 50% at such low MWNTs content. These improvements in properties were attributed to uniform dispersion and possible orientation of nanotube induced by shear stress. It was suggested that the dynamic packing injection molding could provide much strong shear force for better dispersion of MWNTs in PP matrix, on one hand, but breakdown the aspect ratio of MWNTs, on the other.

Mechanical behaviors of polypropylene/carbon nanotube nanocomposites: The effects of loading rate and temperature

“…However, the ultimate elongation slightly decreases with the addition of nanotubes. More recently, Xiao et al determined the tensile and impact behaviors of the PP/MWNT nanocomposites prepared by dynamic packing injection molding [14]. Tensile measurements were performed at room temperature under a cross-head speed of 50 mm/min.…”

“…Melt-compounding is a versatile technique commonly used to manufacture polymers and their composites due to its simplicity, fast production and availability in the plastics industry. The tensile properties of melt-compounded PP/CNT nanocomposites reported in literature were carried out under a constant cross-head speed at room temperature [10,11,13,14]. Lopez Manchado studied the static tensile behavior of PP reinforced with 0.25-1 wt% SWNTs at room temperature under a cross-head speed of 5 mm/min [11].…”

Multi-walled carbon nanotube filled polypropylene nanocomposites based on masterbatch route: Improvement of dispersion and mechanical properties through PP-g-MA addition

“…However, CNT dispersion in non-polar polymers such as polypropylene during melt processing remains a challenge. Techniques such as end-group functionalization [10][11][12], use of ionic surfactants [13], shear mixing [14,15] and plasma coating [16] have been used to improve dispersion and exfoliation of nanotubes in polypropylene matrix. Polypropylene compatibility with fillers has been improved by matrix modification by grafting it with reactive moieties, such as acrylic acid, acrylic esters, and maleic anhydride [17,18].…”

Mechanical reinforcement of poly(1‐butene) using polypropylene‐grafted multiwalled carbon nanotubes

“…The mechanical properties of polyethylene (PE)/CNTs10, 20–25 and polypropylene (PP)/CNTs composites15, 26–33 have been studied extensively. On the other hand, poly(1‐butene) (PB)/CNTs composites have received scant attention.…”