Crack Toughness Behaviour of Multiwalled Carbon Nanotube (MWNT)/Polycarbonate Nanocomposites

Abstract

Summary: The morphology and fracture behaviour of polycarbonate (PC)/multiwalled carbon nanotube (MWNT) composites have been studied by AFM and post‐yield fracture mechanics. The essential work of fracture (EWF) method has been used to distinguish between two terms representing the resistance to crack initiation and crack propagation. A maximum in the non‐essential work of fracture was observed at 2 wt.‐% MWNT, demonstrating enhanced resistance to crack propagation compared to pure PC. At 4 wt.‐% MWNT, a tough‐to‐brittle transition has been observed. The time‐resolved in‐situ strain field analysis revealed that the onset of crack initiation was shifted to a shorter time for nanocomposites with 4 wt.‐% MWNT compared to that with 2 wt.‐%, and thus explained the existence of a tough‐to‐brittle transition in these nanocomposites. magnified image

Creep Behavior of Polystyrene/Fluorohectorite Micro‐ and Nanocomposites

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“…Obtaining commercially viable polymer/CNT-based PNs generally involves achieving efficient dispersion of the CNTs and conventional melt mixing [6,7] is preferred over other techniques because it is fast, simple, free of solvents and contaminants, and more affordable in the plastics industry [8]. Well-dispersed masterbatches (usually containing 10-20 wt.% CNTs) pre-produced in ''ad hoc'' machinery are often used for mixing with polymers as dispersion is more easy to be close to the optimum.…”

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