[P2-67] Multiscale modeling of surface functionalized graphene/polymer nanocomposites: insight into the effect of covalent grafting
Polymer nanocomposites is applied in various industries to improve their mechanical, electrical, thermal properties instead of using pure polymer. In view of improving mechanical properties of polymer nanocomposites, graphene nanosheets is typical reinforcement due to its excellent properties. However, agglomeration of graphene nanosheets in polymer reduces their mechanical and thermal properties. Besides, weak cohesive energy between graphene and polymer by poor van der waals interaction causes slip condition in their interfacial region. To improve their intrinsic weak interfacial strength and dispersion properties between graphene and polymer nanocomposites, surface treatment of graphene such as covalent grafting or functionalization on graphene nanosheets have been generally used in graphene/polymer nanocomposites.
In this study, multiscale modeling approach for pristine and covalently functionalized graphene included polypropylene nanocomposites is implemented. Representative unit cell consists single-layered graphene and polypropylene matrix is modeled with three-dimensional periodic boundary conditions. Different number of covalent grafting on graphene is considered to investigate effect of grafting density. In molecular dynamics simulations, reactive forcefield for hydrocarbon structure is used to describe carbon-carbon bond breakage in graphene. Through statistical ensemble simulations, thermoelastic behavior of graphene/polypropylene nanocomposites are determined with grafting density differences at single-layered graphene interface. For equivalent continuum modeling to account for covalent grafting, the mean field micromechanics model is supplemented to characterize interfacial and interphase properties of nanocomposites in accordance with number of covalent grafting. In heat of vaporization perspective, correlation of covalent grafting and dispersion inside the polymer matrix is examined.
In this study, multiscale modeling approach for pristine and covalently functionalized graphene included polypropylene nanocomposites is implemented. Representative unit cell consists single-layered graphene and polypropylene matrix is modeled with three-dimensional periodic boundary conditions. Different number of covalent grafting on graphene is considered to investigate effect of grafting density. In molecular dynamics simulations, reactive forcefield for hydrocarbon structure is used to describe carbon-carbon bond breakage in graphene. Through statistical ensemble simulations, thermoelastic behavior of graphene/polypropylene nanocomposites are determined with grafting density differences at single-layered graphene interface. For equivalent continuum modeling to account for covalent grafting, the mean field micromechanics model is supplemented to characterize interfacial and interphase properties of nanocomposites in accordance with number of covalent grafting. In heat of vaporization perspective, correlation of covalent grafting and dispersion inside the polymer matrix is examined.