Аннотация:The influence of silicate loading and lateral dimensions on the linear viscoelastic properties of a polystyrene-polyisoprene diblock copolymer is studied. Three thermodynamically equivalent organically modified layered silicates differing in lateral dimension are used. The effect of the domain structure of the block copolymer and the level of dispersion of the layered silicate on the rheological properties are examined by comparing data for the nanocomposites in the ordered and disordered state of the block copolymer. Hybrids prepared with 5 wt. % organically modified fluorohectorite (diameter ~ 10 µ) and montmorillonite (dia. ~ 1 µ), demonstrate a notable decrease in frequency dependence at low frequencies in the disordered state, and are understood in terms of a percolated layered silicate network structure. On the other hand, the viscoelastic properties in the disordered state of a hybrid prepared with 5 wt. % organically modified laponite (dia ~ 30 nm) and those in the ordered state for all nanocomposites, demonstrated only minor changes from that observed for the unfilled polymer.
