Contact: Oleksandr Hondliakh

Funding: DFG (Projektnummer: 554884501)

One of the effective methods for increasing the strength, reliability and durability of polymer composites is their nanomodification based on carbon nanotubes (CNT). The deformation and failure behaviour of such polymer materials depends on the CNT concentration in the polymer and can be fundamentally different from their non-nano-reinforced analogs. There is a “nano-reinforcement paradox”, which consists in the fact that at a relatively low concentration of CNT particles (usually 0.03÷0.1%) the material is strengthened, and with a further increase in the CNT concentration, the strength strongly decreases. The relationship between the concentration and deformation processes on the nanolevel of single CNT particles and the macroscopical mechanical behavior of the reinforced polymer components were insufficiently studied. To solve this issue in detail, it is necessary to develop a multiscale approach based on physically sound models that describe the processes of defect formation and accumulation at the nanoscale, the evolution of their propagation at the microscale and the subsequent determination of nonlinear physical and mechanical characteristics of nanomodified polymers at the macroscale. The development of this multiscale approach will be carried out by experimental studies of the formulation process and the resulting properties of the nanomodified polymers, as well as the numerical modeling of defect formation with the finite element method on nano- and micro-scales. For the description of the formulation process, the influence of the parameters of the ultrasonic dispersion process on the efficiency of CNT dispersion in polymer, as well as the resulting deformation and failure properties of the material will be studied. Тhe online measurements of the deagglomeration kinetics of CNT agglomerates in polymer suspensions will be performed by the spectral extinction method which will be adapted to online measurement during ultrasonic dispersion process. Based on the combination of the obtained experimental and numerical results a multiscale model will be developed which accurately describes the mechanics of nanomodified polymers and formulate new multiscale strength criteria for nanomodified polymers to assess the strength and reliability of produced components.