Stress-strain behavior in chitosan-montmorillonite nanocomposites studied by molecular dynamics simulations
(English)Manuscript (preprint) (Other academic)
We have performed molecular dynamics (MD) simulations to study the mechanical properties of bionanocomposites composed of chitosan (CHS) and montmorillonite (Mnt) clay. The stress-strain behavior and the Young’s modulus are calculated to estimate the mechanical properties of the material. Our results show that the mechanical properties of the CHS-Mnt composites are determined by many factors. The volume fraction and the degree of exfoliation of the clay platelets play the key roles. Meanwhile, the molecular adhesion between the polymer CHS and the Mnt at the wet interface is also a main factor. The stress-strain curve of the partially exfoliated CHS-Mnt composite shows significantly larger stiffness than the fully exfoliated one due to the volume fraction of clay is higher in the former case. The stiffness is slightly improved by adding more polymer in the fully exfoliated complex. We conclude that a higher volume faction of the Mnt is an essential premise to fabricate a high-performance composite material. The composite material structure has been found highly relevant to the mechanical properties. In addition, a strong molecular adhesion between the polymer and the clay would be of great importance for the mechanical properties in the composite material. The work provides insight into how to predict the mechanical properties in polymer-clay nanocomposites and may therefore be helpful for the design of bionanocomposite materials.
Young’s modulus, interface thickness, volume fraction, interlayer distance, degree of exfoliation
Materials Chemistry Physical Chemistry Theoretical Chemistry
Research subject Chemistry; Fibre and Polymer Science; Materials Science and Engineering
IdentifiersURN: urn:nbn:se:kth:diva-166293OAI: oai:DiVA.org:kth-166293DiVA: diva2:810455
QS 20152015-05-072015-05-072015-05-20Bibliographically approved