Effect of Repeat Unit's Composition Ratio on the Properties of a Random Copolymer: A Molecular Dynamics Simulation Study

For thermosetting resins the degree of cross-linking plays a crucial role in the dielectric properties of the resin. In our previous works we confirmed this by simulating the relationship between the dielectric properties of poly(2-(4-benzocyclobutenyl)-divinylbenzene (DVB-S-BCB)) and the degree of cross-linking. In our research described here, we constructed a novel random copolymer with all-hydrocarbon structure based on poly(DVB-S-BCB) by introducing styrene (St) as the second polymerization monomer, thus controlling the number of cross-linking sites in the polymer. The effect of changes in St monomer content (number of cross-linking points) in the polymer chains, i.e. DVB-S-BCB and St, on the dielectric properties of the cured resins was investigated by molecular dynamics simulations. The simulation results showed that increasing the St monomer content in the copolymer, decreasing the cross-linking points, led to an increase in the dielectric constant of the cured resin, in addition to which the copolymer exhibited excellent thermo-mechanical properties. We also tested resin samples prepared by the experimental method and compared them with the simulated data, confirming the reliability of the results within acceptable error limits.