The effects of graphene oxide nanoparticles on the mechanical and thermal properties of polyurethane/polycaprolactone nanocomposites; a molecular dynamics approach

Using molecular dynamics simulations using LAMMPS and other tools, this work examined the effect of graphene oxide nanoparticles on the mechanical and thermal properties (TPs) of polyurethane/polycaprolactone nanocomposites. The simulations examined the atomic, MP, and thermodynamic properties of atomic structures while examining and equilibrating them. After 10 ns of equilibration at 300 K and 1 bar, samples were convergent and the simulation parameters were confirmed. The addition of GO-NPs significantly enhanced TPs and MPs, with optimal improvements observed at a 2 % concentration. Specifically, increasing GO-NP content from 0.5 % to 2 % resulted in increases in heat flux from 680.95 to 714.09 W/m², thermal conductivity from 0.69 to 0.93 W/m·K, and Young's modulus from 5.91 to 6.63 MPa. This is while increasing GO-NP content from 0.5 % to 2 % resulted in decreases in both the mean square displacement and glass transition temperature (Temp) to 0.22 Å²and 318 K, respectively. However, further increasing the GO-NP concentration to 5 % led to a decrease in HF and TC, likely due to nanoparticle agglomeration, which also reduced mechanical strength and increased MSD and Tg. This study underscores the importance of optimizing GO-NP concentration, with 2 % identified as the most effective for enhancing the properties of PU/PCL/GO-NCs.