Preparation of functional polystyrene copolymers through nitroxide mediated polymerization and their applications as...

Polystyrene copolymers containing maleic anhydride or maleic acid functional groups with controlled architectures were prepared through nitroxide mediated polymerization and applied to BaTiO3 nanoparticles as polymeric surface modifiers. Effective surface modification effect of BaTiO3 nanoparticles with the copolymers were observed, as evidenced by TGA, SEM, EDX and FT-IR. Modified BaTiO3 nanoparticles exhibited improved dispersion in toluene, suggesting that the amphiphilic copolymers acted as dispersants. Through the addition of the surface modifier, the viscosity of the BaTiO3/epoxy pastes decreased and the dielectric constants of the resulting nanocomposite films increased. Molecular weight and number of functional groups of the copolymers were important factors to ascertain good processability and high dielectric constants of the composite.