Injection‐molded parts of polypropylene/multi‐wall carbon nanotubes composites with an electrically conductive tridimensional network

Abstract

Polypropylene‐based composites filled with multi‐wall carbon nanotubes (MWCNTs), ranging from 1 to 6 wt%, were obtained by injection molding from a previous masterbatch compounded by twin‐screw extrusion (TSE). Resultant electrical percolation phenomenon was related to the ultrathin structure of the carbon‐based fillers and the high dispersion achieved in the thermoplastic matrix. In particular, conductivity experiments showed a threshold value of 3 wt% (1.3 vol%) of MWCNTs for percolation to occur. Electrical percolation was achieved as a result of the formation of an interconnected three‐dimensional structure compromising a top average inter‐nanotube distance of about 493 nm among isolated nanotubes in polypropylene. The current work is hoped to bear significance toward understanding of the electrical performance for industrial ultrathin carbon black‐based polyolefin composites. POLYM. COMPOS., 37:488–496, 2016. © 2014 Society of Plastics Engineers

Valorization of Linen Processing By-Products for the Development of Injection-Molded Green Composite Pieces of Polylactide with Improved Performance

“…Once the biopolymer was melted by the reciprocating screw against the unmoving barrel wall, a metered dosage of polymer melt was transferred towards the nozzle of the injection unit and then injected into the mold, where the heat from the melt dissipates rapidly. In general, very high shear rates arise in injection molding operations, usually up to 10 4 s −1 [38]. A cavity filling time of 1 s was set during mold cavity filling to optimize the process, whereas a packing time of 10 s during back pressure was used to improve the final quality and properties of the green composite pieces.…”

Electrical and morphological properties of microinjection molded polypropylene/carbon nanocomposites

“…This is attributed to the higher aspect ratio and intrinsically higher electrical conductivity of CNT. In a recent study, Torres‐Giner et al . reported that p c occurs at 3 wt % for PP/CNT composites obtained by conventional injection molding.…”

Preparation and characterization of compression‐molded green composite sheets made of poly(3‐hydroxybutyrate) reinforced with long pita fibers

“…[51] More importantly, due to the lower mixing energies and shear peaks employed during molding methodologies, filler attrition or breakage can be minimized. [52] In this work, pita fibers were originally selected to produce a sustainable LFRT. This hard-type fiber is extracted from the leaves of the agave plant (Agave americana), which is a monocotyledon plant from the sisal family of Agave sisalana.…”