An acrylic-silica hybrid polymeric nanocomposite, comprising well-distributed silica nanoparticles in acrylic matrix, has been synthesized at a markedly rapid rate from a dendritic acrylic oligomer (DAO) and an acrylic-functionalized silica (A-silica) via IN-curing. A-silica was made by functioning colloidal silica nanoparticles with 3-methacryloxypropyltrimethoxysilane (MATMS) and DAO was formed by reacting 1,5-diamino-2-methylpentane (MPMDA) with trimethylopropane triacrylate (TMPTA). The MATMS has been found either doubly or singly bonded to silica nanoparticles but not triply bonded, and the inclusion of MATMS into the siloxane network structure increases the size of silica nanoparticles. The well distribution of A-silica and its good compatibility with DAO cause an increase in T-d of the acrylic-silica hybrid material. Silica nanoparticles are too small to cause any significant light scattering, and do not have deleterious effects on transparency. The "hybrid-on-poly-ethylene terephathalate" films exhibited satisfactory hardness and surface roughness because of silica nanoparticles. The preparation as well as the characterization of the constituting species and the final hybrid material are described in detail. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 8149-8158, 2008