Nanoclay-induced morphology development in chaotic mixing of immiscible polymers

This study investigated the role of layered silicate clay on morphology development in chaotic mixing of two immiscible polymers, polypropylene (PP) and polyamide 6 (PA6). The study showed that clay particles helped to produce droplets of much smaller size and with narrower size distribution due to their direct influence on the breakup of PP domains. In the experiments, a small quantity of organically modified layered silicate clay was initially mixed in PP and the mixture was blended with PA6 in a chaotic mixer. All morphological forms, such as lamellas, fibrils, and droplets were seen as in the case with no clay. The clay particles reduced interfacial tension between PP and PA6 phases. As a consequence, the PP domains sustained lamellar and fibrillar forms, and thin fibrils were formed. These thin fibrils in turn broke rapidly into smaller droplets. It was also found that a large fraction of clay particles migrated into PA6 phase and contained intercalated PA6 chains in their galleries. These results indicate that clay particles did not participate in compatibilization in this system. (c) 2005 Wiley Periodicals, Inc.