In order to improve the thermal conductivity and insulation properties of polypropylene (PP) and to investigate the regulation mechanism

this paper first takes —OH

—COOH

—NH2 grafted graphene as the basis and grafts graphene oxide by polyimide (PI) and its derivatives to form functionalized graphene. Then we dope polypropylene with functionalized graphene

and use molecular dynamics to calculate the thermal conductivity and insulating properties of the composite system at 300 K and to reveal the microscopic mechanism. The results show that the PP-PI-2-NH2 system exhibits the most pronounced improvements in thermal conductivity and relative permittivity compared with the PP system

with the thermal conductivity improved by 201.17% and the relative permittivity reduced by 28.97%; the PP-PI-1-OH system shows the optimal improvement in breakdown field strength

which is increased by 19.18% compared with the PP system. Meanwhile

the microscopic mechanism of the enhancement of the thermal conductivity and dielectric properties of PP by functionalized graphene is revealed from the perspectives of free volume

radial distribution function

phonon density of states

and density flood theory. The results can provide methodological guidance and theoretical reference for improving the thermal conductivity and insulation properties of polypropylene.