We conduct molecular dynamics simulations to investigate the self-assembly process of nano-hybrid materials based on polyhedral oligomeric silsesquioxanes (POSS). POSS molecules consist of an inorganic core, e.g., a cube made of silicon and oxygen atoms, that can be funcitonalized with hydrocarbon chains of different lengths. Here we study mono-functionalized cubes. The resulting building blocks can be further assembled into POSS-hydrocarbon copolymers, with POSS configured as pendent groups to the hydrocarbon backbone. We analyzed the simulated equilibrium structures and dynamics of these composites systems. We determined the mechanical properties of the final composites structures at different temperatures and identified the reinforcement mechanism of POSS in the polymer matrix. Specifically, we will discuss the performance of these materials as a function of the POSS/polymer ratio. We also studied the thermal properties and relaxation behavior of these materials, and compared them to the melting behavior of crystalline mono-tethered POSS systems.