| 초록 |
Various cationic difunctional azo-initiators were synthesized and subsequently intercalated into montmorillonite (MMT), leading to the anchored radical initiator-MMT hybrids. Based on the longer interlayer d-spacing, the ABTBA-MMT hybrid was the best among all. High-impact polystyrene (HIPS)/MMT nanocomposites were prepared via in-situ polymerization of styrene in the presence of polybutadiene, using the ABTBA-MMT hybrid. Incomplete exfoliation of the silicate layers in the HIPS nanocomposites was observed when a bulk polymerization was employed. On the other hand, the silicate layers were efficiently exfoliated in the PS matrix during a solution polymerization, due to the low extra-gallery viscosity, which can facilitate the diffusion of styrene monomers into the clay layers. The nanocomposites exhibited significant improvement in thermal and mechanical properties. For example, about 50 % improvement in Young’s modulus was achieved with 5 wt% of the clay, compared to the unmodified polymer counterpart. The exfoliated HIPS/MMT nanocomposites were characterized by various techniques. |
