Mechanical properties of micro-injected POM/MWCNT nano-composites

The addition of carbon nanotubes (CNT) into a polymeric matrix can strongly affect the properties of the composite. Indeed, due to their high stiffness, excellent conductivity and high aspect ratio, CNT can enhance the mechanical, electrical and thermal properties of the matrix. However, so far most of their properties is not well transferred to the composite due to the mixing process. Moreover, since not only the materials, but also the manufacturing processes affect the final products this paper is focused on the mechanical properties of micro injected specimens of POM/CNT composites. The effect due to the presence of the nanofillers, in two different percentage, is analysed combined with the effect of the manufacturing processes that could be used for a final product manufacturing. Indeed, extrusion and micro injection moulding are two current industrial manufacturing processes and key technologies for the mass production of cheap but highly performing products. Therefore, the capability to combine the properties of the CNT with the easiness of batch processability of polymer would lead to a great technological breakthrough. The results show that the presence of CNT induces a remarkable increase in the mechanical resistance and stiffness, but drastically reduces the material ductility. However this could be due to the presence of undispersed nanotubes. Moreover, both the CNT and mould temperature seems to have an influence on the polymer crystallinity developed during the cooling phase in the micro-moulding process.