Insulating Paper Cellulose with High Mechanical Performance and Low Polarizability: The Effect of Doping Concentration on Polyhedral Oligomeric Silsesquioxanes-Modified Cellulose

To study the effect of doping concentration on polyhedral oligomeric silsesquioxane (POSS)-modified cellulose and its internal mechanism, molecular dynamics is used to establish a pure cellulose model and 1, 2, 3, 4, and 5 wt% POSS-modified cellulose models, and the cohesive energy density and solubility parameter, mechanical properties, free volume, mean square displacement, and polarizability are calculated at 343 K. The simulation results show that the addition of POSS effectively improves the compatibility and mechanical performance of cellulose and at the same time enhances its thermal stability. Among the five modified cellulose models, the modification effect of the 3 wt% POSS-modified cellulose model is the best. It is also found that the addition of POSS effectively reduces the polarizability of cellulose and even the electric field distribution in the oil paper insulation system, so as to enhance the insulation of the transformer. With the increase in concentration, the polarizability decreases.