Polyimide precursor/functionalized carbon nanotubes: molecular modeling and physical properties theoretical evaluation

This article explains the influence of –OH, –COOH, and –NH2 functional groups, bounded to carbon nanotubes, on the interactions occurring in composites having as matrix a polyimide precursor. The molecular modeling is used to visually reveal the optimized conformation of the polyimide precursor structural unit, carbon nanotubes with or without functional groups and corresponding composites where hydrogen bonding interactions is formed. Also, based on molecular modeling, quantitative structure activity relationship parameters and binding energies are calculated, indicating that the interaction energy between the matrix and the filler is greater as the functional group polarizability is higher. The theoretically estimated electrical conductivity of the composites increases by the addition of the filler and it is the highest for the ones containing carbon nanotubes functionalized with –OH. The theoretical analysis of the thermal conductivity of the composites reveals a better heat conduction for the same mentioned filler, being increased during the temperature rise. This kind of study is necessary to predict certain properties of the composites before synthesis, thus avoiding the wasting of raw compounds.