Structure-properties relationship in polymer nanocomposites based on polylactic acid and carbon nanotubes

Abstract

The work investigated the effect of carbon nanotubes (CNTs) on the properties of polylactic acid. It was found that the addition of CNTs does not alter the chemical structure of the polymer, but substantially influences its crystallinity, thermophysical, conductive and mechanical characteristics. Analysis of structural features showed the absence of new chemical bonds, but structural ordering of the matrix and changes in morphology were recorded. It is shown that the degree of crystallinity and melting temperature increase with a CNT content of up to 0.6%, and decrease when this value is exceeded. The electrical conductivity increases significantly after reaching the percolation threshold (0.5%), which indicates the formation of a conductive network. The mechanical properties show a nonlinear dependence with a minimum at a content of 0.5% CNT due to the agglomeration of nanotubes. The results obtained indicate the need to optimize the composition of the composite to achieve the desired characteristics.