Structure ordering and reinforcement in POSS containing hybrids

Abstract

The rubbery Epoxy–POSS (polyhedral oligomeric silsesquioxane) hybrid networks have been prepared by incorporating the novel diepoxy–POSS monomer in an epoxy network. During the hybrid network formation, monitored in situ by SAXS, the POSS units self-assemble to form crystalline lamellae in the epoxy matrix. The ordered organic–inorganic hybrid shows the temperature induced order–order and order–disorder transitions due to breaking the POSS domains. The proposed structural model of the hybrid involves the ordered POSS lamellae and cylinders as well as the disordered arrangement of POSS units. Dynamics of the self-assembly processes was investigated by DMA measured at different frequencies of shear deformation. The well-arranged POSS domains provide the hybrid with a significant reinforcement. Moreover, the hybrid with a high POSS content undergoes a strain induced stiffening due to rearrangement of the ordered structure. The effect of POSS–POSS interactions on the hybrid ordering and reinforcement is discussed.