Dynamics of matrix-free nanocomposites consisting of block copolymer-grafted silica nanoparticles under elongation evaluated through X-ray photon correlation spectroscopy

X-ray photon correlation spectroscopy (XPCS) is a powerful tool for investigating the dynamics of polymer nanocomposites. In this study, XPCS was utilized to analyze matrix-free nanocomposite consisting poly(methyl methacrylate)-b-poly(butyl acrylate)-g-silica nanoparticles (PMMA-b-PBA-g-SiNPs) during uniaxial elongation and stress relaxation. The effect microphase-separated state PMMA-b-PBA on SiNP core in PMMA-b-PBA-g-SiNPs confirmed at initial with temperature-dependence. SiNPs exhibited hyperdiffusive ballistic-like motion temperature range 298–423 K, including temperatures above below glass transition (Tg) outer PMMA layer. velocity increased rapidly when approached Tg PMMA. During elongation, anisotropic between two directions, namely parallel perpendicular elongation. direction faster than those despite small strain, high weight ratio SiNP, large size PMMA-b-PBA-g-SiNPs. A decrease relaxation rate also observed by strain = 0.2, which plastic deformation region.