In order to modifiy the deterioration of epoxy resin properties caused by thermal aging

we studied the effect of thermal aging on the electrical treeing characteristics of nano POSS/EP composites. We prepared nano POSS/EP composites with different mass fractions

conducted a 32-day thermal aging test

and measured the mass loss rate

trap energy level

breakdown field strength

and electrical tree growth characteristics of the samples. Additionally

molecular dynamics simulations were used to model their free volume and mean square displacement. The experimental results show that

at micro-doping levels

the breakdown field strength and electrical tree resistance of the composites increase with the filler ratio

with the most significant improvement in AC breakdown field strength observed at a 3% doping ratio

which is 18% higher than that of the unmodified epoxy resin; after thermal aging

the breakdown field strength only decreases by 3.9%. The electrical tree growth rate

expansion coefficient

and fractal dimension all indicate that the 3% doping ratio has the most significant inhibitory effect on the growth of electrical trees in the composites

enhancing electrical tree resistance; the simulation results show that the free volume and mean square displacement of the POSS/EP composite system are both reduced. The research results can provide a reference for the study of electrical tree characteristics of epoxy resin composites under thermal aging conditions.