Silane coupling agents are widely used to improve the compatibility between nanoparticles and polymers. In this paper

the effects of nano-SiO2 modified by KH550

KH560 and KH792 silane coupling agents on the properties of polypropylene composites are studied by molecular dynamics simulation. The effects of coupling agent on the thermal

mechanical and electrical properties of polypropylene nanocomposites are discussed by analyzing the cohesive energy density

binding energy

free volume

and rotation radius. The results show that the thermal

mechanical and electrical properties of polypropylene nanocomposites are improved after the addition of silane coupling agent modified nano-SiO2. The silane coupling agent not only improves the compatibility between the nanoparticles and the polypropylene matrix

increases the cohesive energy density and the interfacial bonding force

but also affects the motion state of the molecular chain by changing the free volume

thereby changing the glass transition temperature

thermal conductivity

rigidity

toughness

relative dielectric constant and breakdown strength of the polypropylene nanocomposites. In addition

the alkyl coupling agent can also change the electrostatic potential distribution and band gap of nano-SiO2

and further improves the electrical properties.