The Polymer Society of Korea

Abstract

In polymer nanocomposites (PNCs), nanoparticle size strongly influences interfacial interactions and mechanical properties. While most previous studies have focused on monodisperse systems, industrial materials typically exhibit polydispersity. This study investigates the effect of particle size distribution on the microstructure and rheological behavior of PNCs. Silica nanoparticles with average diameters of ~10 nm and ~170 nm were dispersed in a short-chain polymer matrix. The ratio of small to large particles (Rs) was varied to control polydispersity. Rheological measurements and H-NMR analysis were used to evaluate yielding behavior and polymer chain mobility. As Rs increased, the storage modulus (G′) increased, indicating enhanced interfacial interactions and stronger network formation due to the high surface area of small particles. These results highlight particle size distribution as a key parameter for tuning PNC properties.