engleski

Influence of carbon nanotubes functionalization on the mechanical properties of polymethacrylate nanocomposites

Nanocomposites based on poly (methyl methacrylate) (PMMA) and a copolymer of methyl methacrylate and hexyl methacrylate were investigated. The fillers were: multi walled carbon nanotubes (MWCNTs) and functionalized MWCNTs (oxidized). The samples were studied by the depth sensing indentation methods (DSI) based on measurement of load–displacement curves at a constant loading speed. The tests were performed on a dynamic ultra microhardness tester DUH-211S in accordance with ISO 14577-1. The dynamic hardness, Martens hardness, indentation hardness, indentation modulus and elastic part of the deformation work were measured. Classical Vickers hardness was also determined. It was established that the mechanical properties of the polymer matrices have been improved by adding 1% of MWCNTs in spite of their being or not functionalized. The presence of functionalized nanotubes had a particular effect upon the different polymer composites. They improved the micromechanical characteristic for PMMA composites and worsened those of copolymer composites. The following assumptions about the structural peculiarities of the composites investigated have been proposed: the reason for the different effect of the modified carbon nanotubes are the length of the side chains and different interaction ; the long hexyl groups spatially hinder the contact of the ester groups with functionalized MWCNTs and thus facilitate the agglomeration of the latter.

microindentation ; depth sensing indentation ; functionalization ; methacrylate’s nanocomposites ; carbon nanotubes

Glavni autori: Elvira Vidović i Galina Zamfirova