Towards a comprehensive optimization of dielectric and viscoelastic performance of poly(ethylene-co-methyl acrylate) through chain sequence regulation

The increasing request for dielectric polymers is drawing research efforts on designing new copolymers with high energy density and long-term cyclic stability. Herein, the all-atom molecular dynamics simulation coupled with density functional theory is applied to investigate how the chain sequence structure affects the dielectric, viscoelastic, and energy-saving properties of poly(ethylene-co-methyl acrylate). For various chain sequences, their dielectric ratios, actuation sensitivities, and hysteresis loss have been quantitatively evaluated to analyze the corresponding dielectric efficiencies, mechanical flexibilities, and cyclic stabilities, respectively. It is demonstrated that dielectric efficiency is mainly determined by dipolar polarization depending on charge distribution and surface electrostatic potential, while mechanical flexibility is associated with the coupling effect of dielectric strength and Young's modulus. Accordingly, a few of chain sequences with optimized performance have been picked out, providing the guidance for actual syntheses of promising dielectric copolymers. • The properties of poly(ethylene-co-methyl acrylate) were investigated by theoretical calculations. • The comprehensive performances of copolymers can be optimized by regulating chain sequences. • Dielectric efficiency, mechanical flexibility and cyclic stability were considered simultaneously. • Pentablock and alternating copolymers have the most favorable comprehensive performances.