Monodisperse SiC/vinyl ester nanocomposites: Dispersant formulation, synthesis, and characterization

Abstract

A novel dispersant “mono-2-(methacryloyloxy)ethyl succinate” was formulated for dispersing 30-nm SiC nanoparticles in vinyl ester resin. The eight carbon rule was used as the guideline to achieve a particle–particle separation of 20 to 60 nm for colloid stability. Fourier transform infrared spectroscopy was performed to characterize the SiC particle surfaces. Only a negligible amount of oxidized layer was observed; which illustrates that the SiC surface is basic. Thus, the Lewis base-Lewis acid reactions make the functional group–COOH an effective adsorbate to the SiC nanoparticle surface. The organofunctional group “methacrylates,” which exhibits the best wet strength with polyester copolymerizes with styrene monomers in the vinyl ester during cure. Hence, this novel dispersant also acts as an efficient coupling agent that reacts with both SiC and vinyl ester. The monolayer coverage dosage of 62 fractional wt% of the dispersant was used to attain the minimum filled resin viscosity. The multicomponent compositional imaging using atomic force microscopy confirmed the monodisperse SiC nanoparticles in vinyl ester. The 3 vol% SiC reinforced vinyl ester achieved a 75% increase in modulus, 42% increase in strength, and 75% increase in toughness as compared with the neat resin without nanofiller reinforcement.