Atomistic molecular dynamics simulation study on thermomechanical properties of poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane) dielectric insulator for soft electronics

Abstract

While poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane, pV3D3) is a promising dielectric material, synthesized from an iCVD process, the physical properties of pV3D3 film have yet to be studied in detail. In this study, the thermoelastic properties of pV3D3 are investigated by molecular dynamics simulations. An amorphous molecular unit cell of pV3D3 is modeled with periodic boundary conditions. The PCFF force field is applied to describe all the inter- and intramolecular interactions. Through classical ensemble simulations, the mechanical properties including the stress-strain curves in tension and compression are determined. The glass transition temperature and the coefficient of thermal expansion are determined from the simulation of cooling-down from an elevated temperature. The simulation results show that the pV3D3 is in an almost rubbery state near room temperature. Moreover, a clear hydrostatic pressure effect is observed in the compressive loading condition of pV3D3 and its elastic modulus is within the range of typical thermoplastic.