Tuning Mechanical Properties of Block Copolymer/Aluminosilicate Hybrid Materials

In this work the primary mechanical property profiles of a specific class of nano-structured polymer/inorganic hybrid materials are characterized. By utilizing sol-gel aluminosilicate synthesis with amphiphilic polyisoprene-block-poly(ethylene oxide) block copolymers as structure-directing agents, block copolymer/aluminosilicate hybrid materials are prepared with nanometer scale hexagonally packed cylinders and lamellae of the inorganic hybrid components, as evidenced by small-angle X-ray scattering. Systematic thermal and dynamic mechanical analyses are performed on these hybrids as well as on the constituting components. Results reveal two transitions from the low temperature, glassy state of the hybrids into high temperature elastic plateau regions, with moduli that vary over orders of magnitude as a function of composition and morphology. The first transition can be assigned to the glass transition of the PI domains while the second is ascribed to a temperature induced softening of the organic components within the PEO/hybrid domains. The results suggest that in the present nanostructured block copolymer/aluminosilicate hybrid materials composition and morphology provide a powerful tool to tailor mechanical property profiles.